Abstract

Laboratory optical atomic clocks achieve remarkable accuracy (now counted to 18 digits or more), opening possibilities for exploring fundamental physics and enabling new measurements. However, their size and the use of bulk components prevent them from being more widely adopted in applications that require precision timing. By leveraging silicon-chip photonics for integration and to reduce component size and complexity, we demonstrate a compact optical-clock architecture. Here a semiconductor laser is stabilized to an optical transition in a microfabricated rubidium vapor cell, and a pair of interlocked Kerr-microresonator frequency combs provide fully coherent optical division of the clock laser to generate an electronic 22 GHz clock signal with a fractional frequency instability of one part in 1013. These results demonstrate key concepts of how to use silicon-chip devices in future portable and ultraprecise optical clocks.

© 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement

1. INTRODUCTION

Optical atomic clocks, which rely on high-frequency, narrow-linewidth optical transitions to stabilize a clock laser, outperform their microwave counterparts by several orders of magnitude due to their inherently large quality factors [1]. Optical clocks based on laser-cooled and lattice-trapped atoms have demonstrated fractional instabilities at the 1018 level [2], setting stringent new limits on tests of fundamental physics [3,4], and may eventually replace microwave clocks in global timekeeping, navigation, and the definition of the SI second [5]. Despite their excellent performance, optical clocks are almost exclusively operated by metrological institutions and universities due to their large size and complexity.

Although significant progress has been made in reducing the size of laser-cooled atomic clocks to fit inside a mobile trailer [6], applications of these clocks are still limited to metrological clock comparisons and precision geodesy [7]. In contrast, optical oscillators referenced to thermal atomic or molecular vapors can be realized in small form factors and still reach instabilities below 1014 [8,9]. A fully integrated optical clock would benefit many of the applications [10] that currently utilize compact or chip-scale [11] microwave atomic clocks but, until recently, techniques for on-chip laser stabilization to atoms [12] and optical frequency division [13] were not available. Here, we propose and demonstrate an architecture for an integrated optical clock based on an atomic vapor cell implemented on a silicon chip and a microresonator frequency comb (“microcomb”) system for optical frequency division. Experimentally, this consists of a semiconductor laser local oscillator locked to the rubidium-87 two-photon transition at 385.284 THz that is coherently divided down to a 22 GHz clock tone by stabilizing a pair of interlocked microcombs to the local oscillator.

Microcombs, optical-frequency combs that utilize four-wave mixing of a continuous-wave pump laser inside a high-Q optical microresonator, can be made to operate over a wide range of repetition rates, from 10GHz to 1 THz [14]. In addition to their small size, microresonator combs are compatible with wafer-level manufacturing techniques and can operate at relatively low pump powers (tens of milliwatts) [15,16] compared with fiber and free-space frequency combs, making them an ideal choice for compact optical clocks and low-noise oscillators [13,17,18]. As part of prior work in our group, Papp et al. [13] demonstrated the first optical clock based on a microcomb by stabilizing two modes of a 33 GHz silica (SiO2) microresonator to the D2 and D1 optical transitions in Rb at 780 and 795 nm, respectively. However, due to the lack of self-referencing [19], the full stability of the optical standard was not transferred to the microwave domain. Recent progress in the field of microcombs has led to the realization of mode-locked, low-noise comb generation via temporal soliton formation in the resonator [2022]. These dissipative Kerr-soliton (DKS) frequency combs have been used to demonstrate octave-spanning comb operation [23,24], self-referencing [2527], and carrier-offset-frequency (fceo) phase stabilization [2830]. To date, octave-spanning operation has only been demonstrated using combs with 1THz repetition rates, well outside the bandwidth of traditional electronic detectors, a requirement for producing a usable microwave clock signal. To circumvent this issue, our optical clock architecture employs two interlocked microcombs: a high repetition rate, octave-spanning comb used for self-referencing, and a narrowband comb used to produce an electronically detectable microwave output.

2. EXPERIMENTAL METHODS

Figure 1(a) shows a simplified schematic of the experiment. The local oscillator (“clock laser”) for our clock is a 778.1 nm, distributed Bragg reflector (DBR) laser that is referenced to the two-photon transition in 87Rb in a microfabricated vapor cell. We generate a 1 THz repetition rate, octave-spanning, DKS frequency comb by coupling 100mW of pump light from a 1.54 μm external cavity diode laser (ECDL) into a Si3N4 (SiN) microresonator, which is used for coarse optical division. Full stabilization of the SiN comb is accomplished by stabilizing fceo and locking an optical mode of the comb to the clock laser. We independently generate a narrowband, 22 GHz repetition rate, DKS comb by coupling 160mW of light from a 1.556 μm ECDL via tapered optical fiber into a silica microresonator. The two combs are then interlocked, and we use the silica comb as a finely spaced ruler to measure the repetition rate of the SiN comb. The output of the clock is a 22 GHz optical pulse train (and corresponding electrical signal) that is phase-stabilized to the Rb two-photon transition. The techniques for locking the DBR laser to the Rb atoms and stabilizing the frequency combs are detailed in Supplement 1. Figures 1(b)1(d) show images of the main components of the clock: the two microresonators and the Rb cell. All three elements are microfabricated devices, and, in future implementations of the concept introduced here, would support more advanced integration.

 figure: Fig. 1.

Fig. 1. Schematic of the microfabricated photonic optical atomic clock. (a) The microfabricated optical clock consists of an optical local oscillator, a microfabricated Rb vapor cell, and a pair of microresonator frequency combs, which serve as optical clockwork. Absorption of the clock laser in the cell is detected via the collection of 420 nm fluorescence using a microfabricated PMT. The optical clockwork consists of interlocked DKS combs generated using a 2mm diameter, silica microresonator, and a 46 μm diameter, SiN microresonator. Stabilization of the frequency combs’ output is performed via electronic feedback (indicated by dotted lines) to the pump frequency and resonator detuning of the ECDLs used to pump the microresonators. The feedback signals are generated from optical heterodyne beat notes of adjacent comb teeth, as indicated by the solid black arrows. In some cases, frequency doubling (dashed black arrows) was required to compare optical signals. For simplicity, we do not picture the frequency and intensity modulators used for feedback in the comb frequency servo loops. (b) Scanning-electron microscope image of the SiN microresonator. Photographs of (c) the silica microresonator and (d) the microfabricated Rb vapor cell.

Download Full Size | PPT Slide | PDF

The two-photon transition in Rb (Fig. 2 inset) has been studied extensively for use as an optical frequency standard [3134]. Here, we only discuss details of this system relevant to spectroscopy in a microfabricated vapor cell. The clock laser is locked to the 5S1/2 (F=2) to 5D5/2 (F=4) two-photon transition in 87Rb at 778.106 nm (385.284566 THz) using a 3×3×3mm vapor cell [Fig. 1(d)]. The rear window of the cell is covered with a high-reflectivity coating (R=99.8%), which is used to retroreflect the clock laser and provide the counterpropagating beams required to excite the Doppler-free, two-photon transition. The front window is antireflection-coated on both sides to prevent parasitic reflections.

 figure: Fig. 2.

Fig. 2. Spectroscopy of optical clock transition. Doppler-free fluorescence spectroscopy of the optical clock transition between the 5S1/2, F=2 to 5D5/2, F=4 levels at 385.284566 THz, with a full width at half-maximum of 1MHz. The atomic level structure of the 87Rb two-photon transition is shown as an inset.

Download Full Size | PPT Slide | PDF

Excitation of the two-photon transition is detected via fluorescence at 420 nm from the 5D to 6P to 5S decay path by a microfabricated photomultiplier tube (PMT) along the optical axis of the clock laser. Figure 2 shows the output of the PMT as the clock laser is swept across the clock transition. A Lorentzian fit (purple) to the fluorescence signal gives a linewidth of 1MHz, which includes contributions of 330 kHz from the natural linewidth, 475kHz from the laser linewidth, 100kHz of transit time broadening [35], and 100kHz due to collisional broadening from background gases in the cell (see Supplement 1).

Figures 3(a) and 3(b) show optical spectra of the free-running soliton combs. During clock operation, the silica comb pump laser, νGHz,pump, is frequency-doubled and subsequently phase-locked to the clock laser, νRb. The SiN comb tooth at 1556 nm (νTHz,pump-2) is then locked to νGHz,pump. Here, νGHz/THz,pump-n, describes the silica/SiN (GHz/THz) comb tooth n modes on the low-frequency side of the pump. We lock the terahertz comb offset frequency, fceo, with an ECDL-assisted, f-2f interferometer [29]. Simultaneous stabilization of the SiN comb offset frequency and repetition rate (via νTHz,pump-2 locked to νRb) effectively divides the clock laser from 385 to 1 THz. We complete the optical frequency division by phase locking νGHz,pump-48 to νTHz,pump-3 at 1564 nm, which generates a stable, Rb-referenced, 22 GHz clock output tone. Figure 3(c) shows the beat note between the 22 GHz clock output and a 22 GHz signal referenced to a hydrogen maser.

 figure: Fig. 3.

Fig. 3. Microcomb spectra. (a) SiN microresonator comb spectrum, showing the 1 THz comb tooth spacing with a resolution bandwidth of Δλ=0.1nm. An f-2f interferometer (light blue arrow) in which light at 1998 nm is frequency-doubled to heterodyne with the comb teeth in the dispersive wave at 999 nm is used to measure and stabilize the offset frequency, fceo, of the SiN comb (δ=fceo/10MHz). (b) Silica microresonator comb spectrum (light blue) with 22 GHz repetition rate, shown overlaid with three teeth from the 1 THz, SiN comb (dark blue), with a resolution of Δλ=0.02nm. Arrows indicate phase locks used to stabilize the combs. Greek letters show the ratio-of-integer values multiplied by a 10 MHz clock that are used as a reference for each of the phase locks. For the devices used in the experiment, α=154.224, β=3525.29238, γ=539.9808, and δ=1280.0. (c) RF spectrum of the 22 GHz clock output.

Download Full Size | PPT Slide | PDF

The frequency of the clock output, fGHz,rep, is directly linked to the Rb two-photon transition and is given by the simple relationship,

fGHz,rep=vRb+(α/2+2·[(q1)·β+q·γδ])·f10MHz2·q·p,
where νRb is the clock laser frequency, q=190 is the mode number of the SiN comb line closest to the clock transition νTHz,pump-2, and p=48 is the number of 22 GHz comb modes separating the lock points to the SiN comb teeth, νTHz,pump-2, and νTHz,pump-3. The synthesizer frequencies used in each of the phase locks between the comb teeth are defined in terms of the ratios of integers α, β, γ, and δ relative to a 10 MHz clock referenced to a hydrogen maser, f10MHz, as indicated in Fig. 3(b). The denominator in Eq. (1) gives the full division factor of the comb: n=2×48×190=18,240. A crystal oscillator referenced to the free-running repetition rate of the silica comb [Fig. 4(b), open green squares] can instead be used as a reference for phase locking the microcombs, and the clock can be run with no external frequency references.

 figure: Fig. 4.

Fig. 4. Optical clock performance. (a) Time-series measurement of the clock optical frequency offset derived from the 22 GHz clock output frequency, vclock,opt (top, blue) and derived from the beat note against the Er:fiber frequency comb, vlaser (bottom, orange). The reference frequency is νo=385284566370400Hz [34]. Short breaks in the data indicate periods where the clock laser dropped out of lock. (b) Comparison of Allan deviation of 22 GHz clock output for the free-running silica microresonator (green open squares), the fully stabilized comb (blue circles), and the heterodyne beat note of the clock laser with the Er:fiber comb (orange triangles). At long integration times (purple pentagons), the clock stability is limited to 1×1013 due to temperature fluctuations in the lab. Error bars represent a 68% confidence interval. An Allan deviation of a Microsemi chip-scale atomic clock (CSAC) measured against a hydrogen maser is shown for comparison (gray circles). (c) Frequency noise spectra for the free-running and locked clock laser. A large servo bump at 4kHz is evidence of frequency noise spectra. (d) Phase noise away from carrier for the 22 GHz clock output signal (blue), along with the contributions from the intermediate phase locks (red and magenta) and the phase noise of the clock laser calculated from the laser frequency noise spectrum (orange dashed), which gives a lower limit on the phase noise of the 22 GHz clock output.

Download Full Size | PPT Slide | PDF

3. RESULTS AND DISCUSSION

Figure 4 summarizes the performance of the optical clock. Figure 4(a) shows a plot of the 22 GHz clock output measured against the hydrogen maser and multiplied up to the optical domain (blue), along with a plot of the clock laser frequency measured against an auxiliary erbium fiber frequency comb (orange) as an independent confirmation of the clock accuracy. The mean values of the two measurements of the clock frequency agree to within their standard error. The absolute frequency shift of our clock relative to the BIPM accepted value [34], after accounting for the light shift and the Rb–Rb collision shift is Δν2.9±7.9kHz (Δν/ΔνRb8×1012), and is primarily due to the collision shift from background gases in the cell (an uncertainty budget is included in Supplement 1). It is worth noting that this represents the first measurement of an absolute clock transition frequency in a chip-scale vapor cell.

Figure 4(b) shows an Allan deviation of the fully stabilized clock signal [Fig. 4(a), blue] measured against the hydrogen maser along with an Allan deviation of the heterodyne of the clock laser with the fiber frequency comb [Fig. 4(a), orange]. An Allan deviation of the clock laser frequency measured against the fiber comb for 24h measured at a later date [purple] reflects the stability of the clock laser at longer integration times. The measured fractional frequency instability of the microwave output is 4.4×1012/τ1/2 and is limited by frequency noise on the DBR laser [Fig. 4(b)] via the intermodulation effect [36]. At long integration times (>103s), we notice that fluctuations in the clock laser frequency are correlated with the laboratory temperature and limit the ultimate stability of the clock to 1×1013.

Figure 4(d) shows the clock phase noise (along with that of the intermediate phase locks), which is competitive with high-frequency (tens of gigahertz) analog signal generators. At low frequencies (<300Hz), the phase noise is limited by the intrinsic phase noise of the clock laser (consistent with perfect optical division at integration time >1s), while the bump around 1 kHz results from the final phase lock between the silica and SiN combs. The phase noise at high frequencies (>10kHz, outside the bandwidth of the comb-to-comb phase locks) is likely due to the silica comb pump laser [37]. This suggests the clock could be operated as a low-phase noise oscillator by utilizing narrow-linewidth pump sources.

4. CONCLUSION

In summary, we present a clear path towards the future integration of optical atomic clocks by proposing a framework for optical frequency division using microresonator frequency combs and have demonstrated a distributed optical atomic clock with a stability of 4.4×1012/τ1/2, where the critical components of the clock are integrated devices. At present, the stability of our clock is limited by the performance of available, integrated 778 nm sources, but short-term stabilities near 1013 at 1 s may be possible with low-noise lasers. We anticipate that devices such as integrated narrow-linewidth lasers [3840] with fast frequency tuning rates and waveguide-based second-harmonic generators [41] will eventually replace the off-the-shelf components in our clock, making a fully integrated optical atomic clock viable. State-of-the-art chip-scale optical clocks would impact applications, including gravitational and remote sensing, timing and navigation when GPS is unreliable, the synchronization of large aperture networks for long-baseline interferometry [4244] and enable in situ, SI-traceable calibrations of laboratory instruments.

Funding

Defense Advanced Research Projects Agency (DARPA); Atomic Clocks with Enhanced Stability (ACES); Direct On-Chip Digital Optical Synthesis (DODOS); U.S. Department of Defense (DoD).

Acknowledgment

The authors would like to thank J. Burke, N. Lemke, L. Stern, E. Donley, and T. Heavner for helpful discussions, D. Hickstein and J. McGilligan for comments on the manuscript, and S. Schima, A. Dellis, and D. Bopp for their help in the cell fabrication. The views, opinions and/or findings expressed are those of the authors and should not be interpreted as representing the official views or policies of the Department of Defense or the U.S. Government. Any mention of commercial products within NIST web pages is for information only; it does not imply recommendation or endorsement by NIST.

 

See Supplement 1 for supporting content.

REFERENCES

1. S. A. Diddams, T. Udem, J. C. Bergquist, E. A. Curtis, R. E. Drullinger, L. Hollberg, W. M. Itano, W. D. Lee, C. W. Oates, K. R. Vogel, and D. J. Wineland, “An optical clock based on a single trapped 199Hg+ ion,” Science 293, 825–828 (2001). [CrossRef]  

2. M. Schioppo, R. C. Brown, W. F. McGrew, N. Hinkley, R. J. Fasano, K. Beloy, T. H. Yoon, G. Milani, D. Nicolodi, J. A. Sherman, N. B. Phillips, C. W. Oates, and A. D. Ludlow, “Ultrastable optical clock with two cold-atom ensembles,” Nat. Photonics 11, 48–52 (2016). [CrossRef]  

3. T. Rosenband, D. B. Hume, P. O. Schmidt, C. W. Chou, A. Brusch, L. Lorini, W. H. Oskay, R. E. Drullinger, T. M. Fortier, J. E. Stalnaker, S. A. Diddams, W. C. Swann, N. R. Newbury, W. M. Itano, D. J. Wineland, and J. C. Bergquist, “Frequency ratio of Al+ and Hg+ single-ion optical clocks; metrology at the 17th decimal place,” Science 319, 1808–1812 (2008). [CrossRef]  

4. R. M. Godun, P. B. R. Nisbet-Jones, J. M. Jones, S. A. King, L. A. M. Johnson, H. S. Margolis, K. Szymaniec, S. N. Lea, K. Bongs, and P. Gill, “Frequency ratio of two optical clock transitions in 171Yb+ and constraints on the time variation of fundamental constants,” Phys. Rev. Lett. 113, 210801 (2014). [CrossRef]  

5. F. Riehle, “Towards a redefinition of the second based on optical atomic clocks,” Comptes Rendus Phys. 16, 506–515 (2015). [CrossRef]  

6. S. B. Koller, J. Grotti, S. Vogt, A. Al-Masoudi, S. Dörscher, S. Häfner, U. Sterr, and C. Lisdat, “Transportable optical lattice clock with 7×10-17 uncertainty,” Phys. Rev. Lett. 118, 073601 (2017). [CrossRef]  

7. J. Grotti, S. Koller, S. Vogt, S. Häfner, U. Sterr, C. Lisdat, H. Denker, C. Voigt, L. Timmen, A. Rolland, F. N. Baynes, H. S. Margolis, M. Zampaolo, P. Thoumany, M. Pizzocaro, B. Rauf, F. Bregolin, A. Tampellini, P. Barbieri, M. Zucco, G. A. Costanzo, C. Clivati, F. Levi, and D. Calonico, “Geodesy and metrology with a transportable optical clock,” Nat. Phys. 14, 437–441 (2018). [CrossRef]  

8. T. Schuldt, K. Döringshoff, E. V. Kovalchuk, A. Keetman, J. Pahl, A. Peters, and C. Braxmaier, “Development of a compact optical absolute frequency reference for space with 10-15 instability,” Appl. Opt. 56, 1101–1106 (2017). [CrossRef]  

9. K. W. Martin, G. Phelps, N. D. Lemke, M. S. Bigelow, B. Stuhl, M. Wojcik, M. Holt, I. Coddington, M. W. Bishop, and J. H. Burke, “Compact optical atomic clock based on a two-photon transition in rubidium,” Phys. Rev. Appl. 9, 014019 (2018). [CrossRef]  

10. J. R. Vig, “Military applications of high accuracy frequency standards and clocks,” IEEE Trans. Ultrason. Ferroelectr. Freq. Control. 40, 522–527 (1993). [CrossRef]  

11. S. Knappe, V. Shah, P. D. D. Schwindt, L. Hollberg, J. Kitching, L. A. Liew, and J. Moreland, “A microfabricated atomic clock,” Appl. Phys. Lett. 85, 1460–1462 (2004). [CrossRef]  

12. M. T. Hummon, S. Kang, D. G. Bopp, Q. Li, D. A. Westly, S. Kim, C. Fredrick, S. A. Diddams, K. Srinivasan, V. Aksyuk, and J. E. Kitching, “Photonic chip for laser stabilization to an atomic vapor with 10-11 instability,” Optica 5, 443–449 (2018). [CrossRef]  

13. S. B. Papp, K. Beha, P. Del’Haye, F. Quinlan, H. Lee, K. J. Vahala, and S. A. Diddams, “Microresonator frequency comb optical clock,” Optica 1, 10–14 (2014). [CrossRef]  

14. T. J. Kippenberg, A. L. Gaeta, M. Lipson, and M. L. Gorodetsky, “Dissipative Kerr solitons in optical microresonators,” Science 361, eaan8083 (2018). [CrossRef]  

15. J. Liu, A. S. Raja, M. Karpov, B. Ghadiani, M. H. P. Pfeiffer, N. J. Engelsen, H. Guo, M. Zervas, and T. J. Kippenberg, “Ultralow-power chip-based soliton microcombs for photonic integration,” Optica 5, 3–9 (2018). [CrossRef]  

16. B. Stern, X. Ji, Y. Okawachi, A. L. Gaeta, and M. Lipson, “Battery-operated integrated frequency comb generator,” Nature 562, 401–405 (2018). [CrossRef]  

17. A. A. Savchenkov, D. Eliyahu, W. Liang, V. S. Ilchenko, J. Byrd, A. B. Matsko, D. Seidel, and L. Maleki, “Stabilization of a Kerr frequency comb oscillator,” Opt. Lett. 38, 2636–2639 (2013). [CrossRef]  

18. W. Liang, D. Eliyahu, V. S. Ilchenko, A. A. Savchenkov, D. Seidel, L. Maleki, and A. B. Matsko, “High spectral purity Kerr frequency comb radio frequency photonic oscillator,” Nat. Commun. 6, 1–8 (2015). [CrossRef]  

19. D. J. Jones, S. A. Diddams, J. K. Ranka, A. Stentz, R. S. Windeler, J. L. Hall, and S. T. Cundiff, “Carrier-envelope phase control of femtosecond mode-locked lasers and direct optical frequency synthesis,” Science 288, 635–639 (2000). [CrossRef]  

20. T. Herr, V. Brasch, J. D. Jost, C. Y. Wang, N. M. Kondratiev, M. L. Gorodetsky, and T. J. Kippenberg, “Temporal solitons in optical microresonators,” Nat. Photonics 8, 145–152 (2013). [CrossRef]  

21. X. Yi, Q.-F. Yang, X. Zhang, K. Y. Yang, X. Li, and K. Vahala, “Single-mode dispersive waves and soliton microcomb dynamics,” Nat. Commun. 8, 14869 (2017). [CrossRef]  

22. S. Coen, H. G. Randle, T. Sylvestre, and M. Erkintalo, “Modeling of octave-spanning Kerr frequency combs using a generalized mean-field Lugiato-Lefever model,” Opt. Lett. 38, 37–39 (2013). [CrossRef]  

23. Q. Li, T. C. Briles, D. A. Westly, T. E. Drake, J. R. Stone, B. R. Ilic, S. A. Diddams, S. B. Papp, and K. Srinivasan, “Stably accessing octave-spanning microresonator frequency combs in the soliton regime,” Optica 4, 193–203 (2016). [CrossRef]  

24. M. H. P. Pfeiffer, C. Herkommer, J. Liu, H. Guo, M. Karpov, E. Lucas, M. Zervas, and T. J. Kippenberg, “Octave-spanning dissipative Kerr soliton frequency combs in Si3N4 microresonators,” Optica 4, 684–690 (2017). [CrossRef]  

25. J. D. Jost, T. Herr, C. Lecaplain, V. Brasch, M. H. P. Pfeiffer, and T. J. Kippenberg, “Counting the cycles of light using a self-referenced optical microresonator,” Optica 2, 706–711 (2015). [CrossRef]  

26. P. Del’Haye, A. Coillet, T. Fortier, K. Beha, D. C. Cole, K. Y. Yang, H. Lee, K. J. Vahala, S. B. Papp, and S. A. Diddams, “Phase-coherent microwave-to-optical link with a self-referenced microcomb,” Nat. Photonics 10, 516–520 (2016). [CrossRef]  

27. V. Brasch, E. Lucas, J. D. Jost, M. Geiselmann, and T. J. Kippenberg, “Self-referenced photonic chip soliton Kerr frequency comb,” Light: Sci. Appl. 6, e16202 (2017). [CrossRef]  

28. T. E. Drake, T. C. Briles, D. T. Spencer, J. R. Stone, D. R. Carlson, D. D. Hickstein, Q. Li, D. Westly, K. Srinivasan, S. A. Diddams, and S. B. Papp, “A Kerr-microresonator optical clockwork,” arXiv:1811.00581 (2018).

29. T. C. Briles, J. R. Stone, T. E. Drake, D. T. Spencer, C. Frederick, Q. Li, D. A. Westly, B. R. Illic, K. Srinivasan, S. A. Diddams, and S. B. Papp, “Interlocking Kerr-microresonator frequency combs for microwave to optical synthesis,” Opt. Lett. 43, 2933–2936 (2018). [CrossRef]  

30. D. T. Spencer, T. Drake, T. C. Briles, J. Stone, L. C. Sinclair, C. Fredrick, Q. Li, D. Westly, B. R. Ilic, A. Bluestone, N. Volet, T. Komljenovic, L. Chang, S. H. Lee, D. Y. Oh, M.-G. Suh, K. Y. Yang, M. H. P. Pfeiffer, T. J. Kippenberg, E. Norberg, L. Theogarajan, K. Vahala, N. R. Newbury, K. Srinivasan, J. E. Bowers, S. A. Diddams, and S. B. Papp, “An optical-frequency synthesizer using integrated photonics,” Nature 557, 81–85 (2018). [CrossRef]  

31. G. Grynberg and B. Cagnac, “Doppler-free multiphotonic spectroscopy,” Rep. Prog. Phys. 40, 791–841 (1977). [CrossRef]  

32. L. Hilico, R. Felder, D. Touahri, O. Acef, A. Clairon, and F. Biraben, “Metrological features of the rubidium two-photon standards of the BNM-LPTF and Kastler Brossel Laboratories,” Eur. Phys. J. Appl. Phys. 4, 219–225 (1998). [CrossRef]  

33. N. D. Zameroski, G. D. Hager, C. J. Erickson, and J. H. Burke, “Pressure broadening and frequency shift of the 5S 1/2 to 5D 5/2 and 5S 1/2 to 7S 1/2 two photon transitions in 85Rb by the noble gases and N2,” J. Phys. B 47, 225205 (2014). [CrossRef]  

34. J. E. Bernard, A. A. Madej, K. J. Siemsen, L. Marmet, C. Latrasse, D. Touahri, M. Poulin, M. Allard, and M. Tetu, “Absolute frequency measurement of a laser at 1556 nm locked to the 5S1/2-5D5/2 two-photon transition in 87-Rb,” Opt. Commun. 173, 357–364 (2000). [CrossRef]  

35. F. Biraben, M. Bassini, and B. Cagnac, “Line-shapes in Doppler-free two-photon spectroscopy the effect of finite transit time,” J. Phys. 40, 445–455 (1979). [CrossRef]  

36. C. Audoin, V. Candelier, and N. Dimarcq, “A limit to the frequency stability of passive frequency standards due to an intermodulation effect,” IEEE Trans. Instrum. Meas. 40, 121–125 (1991). [CrossRef]  

37. J. R. Stone, T. C. Briles, T. E. Drake, D. T. Spencer, D. R. Carlson, S. A. Diddams, and S. B. Papp, “Thermal and nonlinear dissipative-soliton dynamics in Kerr-microresonator frequency combs,” Phys. Rev. Lett. 121, 63902 (2018). [CrossRef]  

38. S. Gundavarapu, G. M. Brodnik, M. Puckett, T. Huffman, D. Bose, R. Behunin, J. Wu, T. Qiu, C. Pinho, N. Chauhan, J. Nohava, P. T. Rakich, K. D. Nelson, M. Salit, and D. J. Blumenthal, “Sub-hertz fundamental linewidth photonic integrated Brillouin laser,” Nat. Photonics 13, 60–67 (2018). [CrossRef]  

39. H. Guan, A. Novack, T. Galfsky, M. Yangjin, S. Fathololoumi, A. Horth, T. Huynh, J. Roman, R. Shi, M. Caverley, Y. Liu, T. Baehr-Jones, K. Bergman, and M. Hochberg, “Widely-tunable, narrow-linewidth III-V/silicon hybrid external-cavity laser for coherent communication,” Opt. Express 26, 7920–7933 (2018). [CrossRef]  

40. P. A. Morton and M. J. Morton, “High-power, ultra-low noise hybrid lasers for microwave photonics and optical sensing,” J. Lightwave Technol. 36, 5048–5057 (2018). [CrossRef]  

41. X. Guo, C.-L. Zou, and H. X. Tang, “Second-harmonic generation in aluminum nitride microrings with 2500%/W conversion efficiency,” Optica 3, 1126–1131 (2016). [CrossRef]  

42. F. Riehle, “Optical clock networks,” Nat. Photonics 11, 25–31 (2017). [CrossRef]  

43. J. Ye, J.-L. Peng, R. J. Jones, K. W. Holman, J. L. Hall, D. J. Jones, S. A. Diddams, J. Kitching, S. Bize, J. C. Bergquist, L. W. Hollberg, L. Robertsson, and L.-S. Ma, “Delivery of high-stability optical and microwave frequency standards over an optical fiber network,” J. Opt. Soc. Am. B 20, 1459–1467 (2003). [CrossRef]  

44. C. Clivati, G. A. Costanzo, M. Frittelli, F. Levi, A. Mura, M. Zucco, R. Ambrosini, C. Bortolotti, F. Perini, M. Roma, and D. Calonico, “A coherent fiber link for very long baseline interferometry,” IEEE Trans. Ultrason. Ferroelectr. Freq. Control 62, 1907–1912 (2015). [CrossRef]  

References

  • View by:

  1. S. A. Diddams, T. Udem, J. C. Bergquist, E. A. Curtis, R. E. Drullinger, L. Hollberg, W. M. Itano, W. D. Lee, C. W. Oates, K. R. Vogel, and D. J. Wineland, “An optical clock based on a single trapped 199Hg+ ion,” Science 293, 825–828 (2001).
    [Crossref]
  2. M. Schioppo, R. C. Brown, W. F. McGrew, N. Hinkley, R. J. Fasano, K. Beloy, T. H. Yoon, G. Milani, D. Nicolodi, J. A. Sherman, N. B. Phillips, C. W. Oates, and A. D. Ludlow, “Ultrastable optical clock with two cold-atom ensembles,” Nat. Photonics 11, 48–52 (2016).
    [Crossref]
  3. T. Rosenband, D. B. Hume, P. O. Schmidt, C. W. Chou, A. Brusch, L. Lorini, W. H. Oskay, R. E. Drullinger, T. M. Fortier, J. E. Stalnaker, S. A. Diddams, W. C. Swann, N. R. Newbury, W. M. Itano, D. J. Wineland, and J. C. Bergquist, “Frequency ratio of Al+ and Hg+ single-ion optical clocks; metrology at the 17th decimal place,” Science 319, 1808–1812 (2008).
    [Crossref]
  4. R. M. Godun, P. B. R. Nisbet-Jones, J. M. Jones, S. A. King, L. A. M. Johnson, H. S. Margolis, K. Szymaniec, S. N. Lea, K. Bongs, and P. Gill, “Frequency ratio of two optical clock transitions in 171Yb+ and constraints on the time variation of fundamental constants,” Phys. Rev. Lett. 113, 210801 (2014).
    [Crossref]
  5. F. Riehle, “Towards a redefinition of the second based on optical atomic clocks,” Comptes Rendus Phys. 16, 506–515 (2015).
    [Crossref]
  6. S. B. Koller, J. Grotti, S. Vogt, A. Al-Masoudi, S. Dörscher, S. Häfner, U. Sterr, and C. Lisdat, “Transportable optical lattice clock with 7×10-17 uncertainty,” Phys. Rev. Lett. 118, 073601 (2017).
    [Crossref]
  7. J. Grotti, S. Koller, S. Vogt, S. Häfner, U. Sterr, C. Lisdat, H. Denker, C. Voigt, L. Timmen, A. Rolland, F. N. Baynes, H. S. Margolis, M. Zampaolo, P. Thoumany, M. Pizzocaro, B. Rauf, F. Bregolin, A. Tampellini, P. Barbieri, M. Zucco, G. A. Costanzo, C. Clivati, F. Levi, and D. Calonico, “Geodesy and metrology with a transportable optical clock,” Nat. Phys. 14, 437–441 (2018).
    [Crossref]
  8. T. Schuldt, K. Döringshoff, E. V. Kovalchuk, A. Keetman, J. Pahl, A. Peters, and C. Braxmaier, “Development of a compact optical absolute frequency reference for space with 10-15 instability,” Appl. Opt. 56, 1101–1106 (2017).
    [Crossref]
  9. K. W. Martin, G. Phelps, N. D. Lemke, M. S. Bigelow, B. Stuhl, M. Wojcik, M. Holt, I. Coddington, M. W. Bishop, and J. H. Burke, “Compact optical atomic clock based on a two-photon transition in rubidium,” Phys. Rev. Appl. 9, 014019 (2018).
    [Crossref]
  10. J. R. Vig, “Military applications of high accuracy frequency standards and clocks,” IEEE Trans. Ultrason. Ferroelectr. Freq. Control. 40, 522–527 (1993).
    [Crossref]
  11. S. Knappe, V. Shah, P. D. D. Schwindt, L. Hollberg, J. Kitching, L. A. Liew, and J. Moreland, “A microfabricated atomic clock,” Appl. Phys. Lett. 85, 1460–1462 (2004).
    [Crossref]
  12. M. T. Hummon, S. Kang, D. G. Bopp, Q. Li, D. A. Westly, S. Kim, C. Fredrick, S. A. Diddams, K. Srinivasan, V. Aksyuk, and J. E. Kitching, “Photonic chip for laser stabilization to an atomic vapor with 10-11 instability,” Optica 5, 443–449 (2018).
    [Crossref]
  13. S. B. Papp, K. Beha, P. Del’Haye, F. Quinlan, H. Lee, K. J. Vahala, and S. A. Diddams, “Microresonator frequency comb optical clock,” Optica 1, 10–14 (2014).
    [Crossref]
  14. T. J. Kippenberg, A. L. Gaeta, M. Lipson, and M. L. Gorodetsky, “Dissipative Kerr solitons in optical microresonators,” Science 361, eaan8083 (2018).
    [Crossref]
  15. J. Liu, A. S. Raja, M. Karpov, B. Ghadiani, M. H. P. Pfeiffer, N. J. Engelsen, H. Guo, M. Zervas, and T. J. Kippenberg, “Ultralow-power chip-based soliton microcombs for photonic integration,” Optica 5, 3–9 (2018).
    [Crossref]
  16. B. Stern, X. Ji, Y. Okawachi, A. L. Gaeta, and M. Lipson, “Battery-operated integrated frequency comb generator,” Nature 562, 401–405 (2018).
    [Crossref]
  17. A. A. Savchenkov, D. Eliyahu, W. Liang, V. S. Ilchenko, J. Byrd, A. B. Matsko, D. Seidel, and L. Maleki, “Stabilization of a Kerr frequency comb oscillator,” Opt. Lett. 38, 2636–2639 (2013).
    [Crossref]
  18. W. Liang, D. Eliyahu, V. S. Ilchenko, A. A. Savchenkov, D. Seidel, L. Maleki, and A. B. Matsko, “High spectral purity Kerr frequency comb radio frequency photonic oscillator,” Nat. Commun. 6, 1–8 (2015).
    [Crossref]
  19. D. J. Jones, S. A. Diddams, J. K. Ranka, A. Stentz, R. S. Windeler, J. L. Hall, and S. T. Cundiff, “Carrier-envelope phase control of femtosecond mode-locked lasers and direct optical frequency synthesis,” Science 288, 635–639 (2000).
    [Crossref]
  20. T. Herr, V. Brasch, J. D. Jost, C. Y. Wang, N. M. Kondratiev, M. L. Gorodetsky, and T. J. Kippenberg, “Temporal solitons in optical microresonators,” Nat. Photonics 8, 145–152 (2013).
    [Crossref]
  21. X. Yi, Q.-F. Yang, X. Zhang, K. Y. Yang, X. Li, and K. Vahala, “Single-mode dispersive waves and soliton microcomb dynamics,” Nat. Commun. 8, 14869 (2017).
    [Crossref]
  22. S. Coen, H. G. Randle, T. Sylvestre, and M. Erkintalo, “Modeling of octave-spanning Kerr frequency combs using a generalized mean-field Lugiato-Lefever model,” Opt. Lett. 38, 37–39 (2013).
    [Crossref]
  23. Q. Li, T. C. Briles, D. A. Westly, T. E. Drake, J. R. Stone, B. R. Ilic, S. A. Diddams, S. B. Papp, and K. Srinivasan, “Stably accessing octave-spanning microresonator frequency combs in the soliton regime,” Optica 4, 193–203 (2016).
    [Crossref]
  24. M. H. P. Pfeiffer, C. Herkommer, J. Liu, H. Guo, M. Karpov, E. Lucas, M. Zervas, and T. J. Kippenberg, “Octave-spanning dissipative Kerr soliton frequency combs in Si3N4 microresonators,” Optica 4, 684–690 (2017).
    [Crossref]
  25. J. D. Jost, T. Herr, C. Lecaplain, V. Brasch, M. H. P. Pfeiffer, and T. J. Kippenberg, “Counting the cycles of light using a self-referenced optical microresonator,” Optica 2, 706–711 (2015).
    [Crossref]
  26. P. Del’Haye, A. Coillet, T. Fortier, K. Beha, D. C. Cole, K. Y. Yang, H. Lee, K. J. Vahala, S. B. Papp, and S. A. Diddams, “Phase-coherent microwave-to-optical link with a self-referenced microcomb,” Nat. Photonics 10, 516–520 (2016).
    [Crossref]
  27. V. Brasch, E. Lucas, J. D. Jost, M. Geiselmann, and T. J. Kippenberg, “Self-referenced photonic chip soliton Kerr frequency comb,” Light: Sci. Appl. 6, e16202 (2017).
    [Crossref]
  28. T. E. Drake, T. C. Briles, D. T. Spencer, J. R. Stone, D. R. Carlson, D. D. Hickstein, Q. Li, D. Westly, K. Srinivasan, S. A. Diddams, and S. B. Papp, “A Kerr-microresonator optical clockwork,” arXiv:1811.00581 (2018).
  29. T. C. Briles, J. R. Stone, T. E. Drake, D. T. Spencer, C. Frederick, Q. Li, D. A. Westly, B. R. Illic, K. Srinivasan, S. A. Diddams, and S. B. Papp, “Interlocking Kerr-microresonator frequency combs for microwave to optical synthesis,” Opt. Lett. 43, 2933–2936 (2018).
    [Crossref]
  30. D. T. Spencer, T. Drake, T. C. Briles, J. Stone, L. C. Sinclair, C. Fredrick, Q. Li, D. Westly, B. R. Ilic, A. Bluestone, N. Volet, T. Komljenovic, L. Chang, S. H. Lee, D. Y. Oh, M.-G. Suh, K. Y. Yang, M. H. P. Pfeiffer, T. J. Kippenberg, E. Norberg, L. Theogarajan, K. Vahala, N. R. Newbury, K. Srinivasan, J. E. Bowers, S. A. Diddams, and S. B. Papp, “An optical-frequency synthesizer using integrated photonics,” Nature 557, 81–85 (2018).
    [Crossref]
  31. G. Grynberg and B. Cagnac, “Doppler-free multiphotonic spectroscopy,” Rep. Prog. Phys. 40, 791–841 (1977).
    [Crossref]
  32. L. Hilico, R. Felder, D. Touahri, O. Acef, A. Clairon, and F. Biraben, “Metrological features of the rubidium two-photon standards of the BNM-LPTF and Kastler Brossel Laboratories,” Eur. Phys. J. Appl. Phys. 4, 219–225 (1998).
    [Crossref]
  33. N. D. Zameroski, G. D. Hager, C. J. Erickson, and J. H. Burke, “Pressure broadening and frequency shift of the 5S 1/2 to 5D 5/2 and 5S 1/2 to 7S 1/2 two photon transitions in 85Rb by the noble gases and N2,” J. Phys. B 47, 225205 (2014).
    [Crossref]
  34. J. E. Bernard, A. A. Madej, K. J. Siemsen, L. Marmet, C. Latrasse, D. Touahri, M. Poulin, M. Allard, and M. Tetu, “Absolute frequency measurement of a laser at 1556  nm locked to the 5S1/2-5D5/2 two-photon transition in 87-Rb,” Opt. Commun. 173, 357–364 (2000).
    [Crossref]
  35. F. Biraben, M. Bassini, and B. Cagnac, “Line-shapes in Doppler-free two-photon spectroscopy the effect of finite transit time,” J. Phys. 40, 445–455 (1979).
    [Crossref]
  36. C. Audoin, V. Candelier, and N. Dimarcq, “A limit to the frequency stability of passive frequency standards due to an intermodulation effect,” IEEE Trans. Instrum. Meas. 40, 121–125 (1991).
    [Crossref]
  37. J. R. Stone, T. C. Briles, T. E. Drake, D. T. Spencer, D. R. Carlson, S. A. Diddams, and S. B. Papp, “Thermal and nonlinear dissipative-soliton dynamics in Kerr-microresonator frequency combs,” Phys. Rev. Lett. 121, 63902 (2018).
    [Crossref]
  38. S. Gundavarapu, G. M. Brodnik, M. Puckett, T. Huffman, D. Bose, R. Behunin, J. Wu, T. Qiu, C. Pinho, N. Chauhan, J. Nohava, P. T. Rakich, K. D. Nelson, M. Salit, and D. J. Blumenthal, “Sub-hertz fundamental linewidth photonic integrated Brillouin laser,” Nat. Photonics 13, 60–67 (2018).
    [Crossref]
  39. H. Guan, A. Novack, T. Galfsky, M. Yangjin, S. Fathololoumi, A. Horth, T. Huynh, J. Roman, R. Shi, M. Caverley, Y. Liu, T. Baehr-Jones, K. Bergman, and M. Hochberg, “Widely-tunable, narrow-linewidth III-V/silicon hybrid external-cavity laser for coherent communication,” Opt. Express 26, 7920–7933 (2018).
    [Crossref]
  40. P. A. Morton and M. J. Morton, “High-power, ultra-low noise hybrid lasers for microwave photonics and optical sensing,” J. Lightwave Technol. 36, 5048–5057 (2018).
    [Crossref]
  41. X. Guo, C.-L. Zou, and H. X. Tang, “Second-harmonic generation in aluminum nitride microrings with 2500%/W conversion efficiency,” Optica 3, 1126–1131 (2016).
    [Crossref]
  42. F. Riehle, “Optical clock networks,” Nat. Photonics 11, 25–31 (2017).
    [Crossref]
  43. J. Ye, J.-L. Peng, R. J. Jones, K. W. Holman, J. L. Hall, D. J. Jones, S. A. Diddams, J. Kitching, S. Bize, J. C. Bergquist, L. W. Hollberg, L. Robertsson, and L.-S. Ma, “Delivery of high-stability optical and microwave frequency standards over an optical fiber network,” J. Opt. Soc. Am. B 20, 1459–1467 (2003).
    [Crossref]
  44. C. Clivati, G. A. Costanzo, M. Frittelli, F. Levi, A. Mura, M. Zucco, R. Ambrosini, C. Bortolotti, F. Perini, M. Roma, and D. Calonico, “A coherent fiber link for very long baseline interferometry,” IEEE Trans. Ultrason. Ferroelectr. Freq. Control 62, 1907–1912 (2015).
    [Crossref]

2018 (12)

J. Grotti, S. Koller, S. Vogt, S. Häfner, U. Sterr, C. Lisdat, H. Denker, C. Voigt, L. Timmen, A. Rolland, F. N. Baynes, H. S. Margolis, M. Zampaolo, P. Thoumany, M. Pizzocaro, B. Rauf, F. Bregolin, A. Tampellini, P. Barbieri, M. Zucco, G. A. Costanzo, C. Clivati, F. Levi, and D. Calonico, “Geodesy and metrology with a transportable optical clock,” Nat. Phys. 14, 437–441 (2018).
[Crossref]

K. W. Martin, G. Phelps, N. D. Lemke, M. S. Bigelow, B. Stuhl, M. Wojcik, M. Holt, I. Coddington, M. W. Bishop, and J. H. Burke, “Compact optical atomic clock based on a two-photon transition in rubidium,” Phys. Rev. Appl. 9, 014019 (2018).
[Crossref]

M. T. Hummon, S. Kang, D. G. Bopp, Q. Li, D. A. Westly, S. Kim, C. Fredrick, S. A. Diddams, K. Srinivasan, V. Aksyuk, and J. E. Kitching, “Photonic chip for laser stabilization to an atomic vapor with 10-11 instability,” Optica 5, 443–449 (2018).
[Crossref]

T. J. Kippenberg, A. L. Gaeta, M. Lipson, and M. L. Gorodetsky, “Dissipative Kerr solitons in optical microresonators,” Science 361, eaan8083 (2018).
[Crossref]

J. Liu, A. S. Raja, M. Karpov, B. Ghadiani, M. H. P. Pfeiffer, N. J. Engelsen, H. Guo, M. Zervas, and T. J. Kippenberg, “Ultralow-power chip-based soliton microcombs for photonic integration,” Optica 5, 3–9 (2018).
[Crossref]

B. Stern, X. Ji, Y. Okawachi, A. L. Gaeta, and M. Lipson, “Battery-operated integrated frequency comb generator,” Nature 562, 401–405 (2018).
[Crossref]

T. C. Briles, J. R. Stone, T. E. Drake, D. T. Spencer, C. Frederick, Q. Li, D. A. Westly, B. R. Illic, K. Srinivasan, S. A. Diddams, and S. B. Papp, “Interlocking Kerr-microresonator frequency combs for microwave to optical synthesis,” Opt. Lett. 43, 2933–2936 (2018).
[Crossref]

D. T. Spencer, T. Drake, T. C. Briles, J. Stone, L. C. Sinclair, C. Fredrick, Q. Li, D. Westly, B. R. Ilic, A. Bluestone, N. Volet, T. Komljenovic, L. Chang, S. H. Lee, D. Y. Oh, M.-G. Suh, K. Y. Yang, M. H. P. Pfeiffer, T. J. Kippenberg, E. Norberg, L. Theogarajan, K. Vahala, N. R. Newbury, K. Srinivasan, J. E. Bowers, S. A. Diddams, and S. B. Papp, “An optical-frequency synthesizer using integrated photonics,” Nature 557, 81–85 (2018).
[Crossref]

J. R. Stone, T. C. Briles, T. E. Drake, D. T. Spencer, D. R. Carlson, S. A. Diddams, and S. B. Papp, “Thermal and nonlinear dissipative-soliton dynamics in Kerr-microresonator frequency combs,” Phys. Rev. Lett. 121, 63902 (2018).
[Crossref]

S. Gundavarapu, G. M. Brodnik, M. Puckett, T. Huffman, D. Bose, R. Behunin, J. Wu, T. Qiu, C. Pinho, N. Chauhan, J. Nohava, P. T. Rakich, K. D. Nelson, M. Salit, and D. J. Blumenthal, “Sub-hertz fundamental linewidth photonic integrated Brillouin laser,” Nat. Photonics 13, 60–67 (2018).
[Crossref]

H. Guan, A. Novack, T. Galfsky, M. Yangjin, S. Fathololoumi, A. Horth, T. Huynh, J. Roman, R. Shi, M. Caverley, Y. Liu, T. Baehr-Jones, K. Bergman, and M. Hochberg, “Widely-tunable, narrow-linewidth III-V/silicon hybrid external-cavity laser for coherent communication,” Opt. Express 26, 7920–7933 (2018).
[Crossref]

P. A. Morton and M. J. Morton, “High-power, ultra-low noise hybrid lasers for microwave photonics and optical sensing,” J. Lightwave Technol. 36, 5048–5057 (2018).
[Crossref]

2017 (6)

F. Riehle, “Optical clock networks,” Nat. Photonics 11, 25–31 (2017).
[Crossref]

V. Brasch, E. Lucas, J. D. Jost, M. Geiselmann, and T. J. Kippenberg, “Self-referenced photonic chip soliton Kerr frequency comb,” Light: Sci. Appl. 6, e16202 (2017).
[Crossref]

X. Yi, Q.-F. Yang, X. Zhang, K. Y. Yang, X. Li, and K. Vahala, “Single-mode dispersive waves and soliton microcomb dynamics,” Nat. Commun. 8, 14869 (2017).
[Crossref]

M. H. P. Pfeiffer, C. Herkommer, J. Liu, H. Guo, M. Karpov, E. Lucas, M. Zervas, and T. J. Kippenberg, “Octave-spanning dissipative Kerr soliton frequency combs in Si3N4 microresonators,” Optica 4, 684–690 (2017).
[Crossref]

T. Schuldt, K. Döringshoff, E. V. Kovalchuk, A. Keetman, J. Pahl, A. Peters, and C. Braxmaier, “Development of a compact optical absolute frequency reference for space with 10-15 instability,” Appl. Opt. 56, 1101–1106 (2017).
[Crossref]

S. B. Koller, J. Grotti, S. Vogt, A. Al-Masoudi, S. Dörscher, S. Häfner, U. Sterr, and C. Lisdat, “Transportable optical lattice clock with 7×10-17 uncertainty,” Phys. Rev. Lett. 118, 073601 (2017).
[Crossref]

2016 (4)

M. Schioppo, R. C. Brown, W. F. McGrew, N. Hinkley, R. J. Fasano, K. Beloy, T. H. Yoon, G. Milani, D. Nicolodi, J. A. Sherman, N. B. Phillips, C. W. Oates, and A. D. Ludlow, “Ultrastable optical clock with two cold-atom ensembles,” Nat. Photonics 11, 48–52 (2016).
[Crossref]

Q. Li, T. C. Briles, D. A. Westly, T. E. Drake, J. R. Stone, B. R. Ilic, S. A. Diddams, S. B. Papp, and K. Srinivasan, “Stably accessing octave-spanning microresonator frequency combs in the soliton regime,” Optica 4, 193–203 (2016).
[Crossref]

P. Del’Haye, A. Coillet, T. Fortier, K. Beha, D. C. Cole, K. Y. Yang, H. Lee, K. J. Vahala, S. B. Papp, and S. A. Diddams, “Phase-coherent microwave-to-optical link with a self-referenced microcomb,” Nat. Photonics 10, 516–520 (2016).
[Crossref]

X. Guo, C.-L. Zou, and H. X. Tang, “Second-harmonic generation in aluminum nitride microrings with 2500%/W conversion efficiency,” Optica 3, 1126–1131 (2016).
[Crossref]

2015 (4)

C. Clivati, G. A. Costanzo, M. Frittelli, F. Levi, A. Mura, M. Zucco, R. Ambrosini, C. Bortolotti, F. Perini, M. Roma, and D. Calonico, “A coherent fiber link for very long baseline interferometry,” IEEE Trans. Ultrason. Ferroelectr. Freq. Control 62, 1907–1912 (2015).
[Crossref]

J. D. Jost, T. Herr, C. Lecaplain, V. Brasch, M. H. P. Pfeiffer, and T. J. Kippenberg, “Counting the cycles of light using a self-referenced optical microresonator,” Optica 2, 706–711 (2015).
[Crossref]

W. Liang, D. Eliyahu, V. S. Ilchenko, A. A. Savchenkov, D. Seidel, L. Maleki, and A. B. Matsko, “High spectral purity Kerr frequency comb radio frequency photonic oscillator,” Nat. Commun. 6, 1–8 (2015).
[Crossref]

F. Riehle, “Towards a redefinition of the second based on optical atomic clocks,” Comptes Rendus Phys. 16, 506–515 (2015).
[Crossref]

2014 (3)

R. M. Godun, P. B. R. Nisbet-Jones, J. M. Jones, S. A. King, L. A. M. Johnson, H. S. Margolis, K. Szymaniec, S. N. Lea, K. Bongs, and P. Gill, “Frequency ratio of two optical clock transitions in 171Yb+ and constraints on the time variation of fundamental constants,” Phys. Rev. Lett. 113, 210801 (2014).
[Crossref]

S. B. Papp, K. Beha, P. Del’Haye, F. Quinlan, H. Lee, K. J. Vahala, and S. A. Diddams, “Microresonator frequency comb optical clock,” Optica 1, 10–14 (2014).
[Crossref]

N. D. Zameroski, G. D. Hager, C. J. Erickson, and J. H. Burke, “Pressure broadening and frequency shift of the 5S 1/2 to 5D 5/2 and 5S 1/2 to 7S 1/2 two photon transitions in 85Rb by the noble gases and N2,” J. Phys. B 47, 225205 (2014).
[Crossref]

2013 (3)

2008 (1)

T. Rosenband, D. B. Hume, P. O. Schmidt, C. W. Chou, A. Brusch, L. Lorini, W. H. Oskay, R. E. Drullinger, T. M. Fortier, J. E. Stalnaker, S. A. Diddams, W. C. Swann, N. R. Newbury, W. M. Itano, D. J. Wineland, and J. C. Bergquist, “Frequency ratio of Al+ and Hg+ single-ion optical clocks; metrology at the 17th decimal place,” Science 319, 1808–1812 (2008).
[Crossref]

2004 (1)

S. Knappe, V. Shah, P. D. D. Schwindt, L. Hollberg, J. Kitching, L. A. Liew, and J. Moreland, “A microfabricated atomic clock,” Appl. Phys. Lett. 85, 1460–1462 (2004).
[Crossref]

2003 (1)

2001 (1)

S. A. Diddams, T. Udem, J. C. Bergquist, E. A. Curtis, R. E. Drullinger, L. Hollberg, W. M. Itano, W. D. Lee, C. W. Oates, K. R. Vogel, and D. J. Wineland, “An optical clock based on a single trapped 199Hg+ ion,” Science 293, 825–828 (2001).
[Crossref]

2000 (2)

D. J. Jones, S. A. Diddams, J. K. Ranka, A. Stentz, R. S. Windeler, J. L. Hall, and S. T. Cundiff, “Carrier-envelope phase control of femtosecond mode-locked lasers and direct optical frequency synthesis,” Science 288, 635–639 (2000).
[Crossref]

J. E. Bernard, A. A. Madej, K. J. Siemsen, L. Marmet, C. Latrasse, D. Touahri, M. Poulin, M. Allard, and M. Tetu, “Absolute frequency measurement of a laser at 1556  nm locked to the 5S1/2-5D5/2 two-photon transition in 87-Rb,” Opt. Commun. 173, 357–364 (2000).
[Crossref]

1998 (1)

L. Hilico, R. Felder, D. Touahri, O. Acef, A. Clairon, and F. Biraben, “Metrological features of the rubidium two-photon standards of the BNM-LPTF and Kastler Brossel Laboratories,” Eur. Phys. J. Appl. Phys. 4, 219–225 (1998).
[Crossref]

1993 (1)

J. R. Vig, “Military applications of high accuracy frequency standards and clocks,” IEEE Trans. Ultrason. Ferroelectr. Freq. Control. 40, 522–527 (1993).
[Crossref]

1991 (1)

C. Audoin, V. Candelier, and N. Dimarcq, “A limit to the frequency stability of passive frequency standards due to an intermodulation effect,” IEEE Trans. Instrum. Meas. 40, 121–125 (1991).
[Crossref]

1979 (1)

F. Biraben, M. Bassini, and B. Cagnac, “Line-shapes in Doppler-free two-photon spectroscopy the effect of finite transit time,” J. Phys. 40, 445–455 (1979).
[Crossref]

1977 (1)

G. Grynberg and B. Cagnac, “Doppler-free multiphotonic spectroscopy,” Rep. Prog. Phys. 40, 791–841 (1977).
[Crossref]

Acef, O.

L. Hilico, R. Felder, D. Touahri, O. Acef, A. Clairon, and F. Biraben, “Metrological features of the rubidium two-photon standards of the BNM-LPTF and Kastler Brossel Laboratories,” Eur. Phys. J. Appl. Phys. 4, 219–225 (1998).
[Crossref]

Aksyuk, V.

Allard, M.

J. E. Bernard, A. A. Madej, K. J. Siemsen, L. Marmet, C. Latrasse, D. Touahri, M. Poulin, M. Allard, and M. Tetu, “Absolute frequency measurement of a laser at 1556  nm locked to the 5S1/2-5D5/2 two-photon transition in 87-Rb,” Opt. Commun. 173, 357–364 (2000).
[Crossref]

Al-Masoudi, A.

S. B. Koller, J. Grotti, S. Vogt, A. Al-Masoudi, S. Dörscher, S. Häfner, U. Sterr, and C. Lisdat, “Transportable optical lattice clock with 7×10-17 uncertainty,” Phys. Rev. Lett. 118, 073601 (2017).
[Crossref]

Ambrosini, R.

C. Clivati, G. A. Costanzo, M. Frittelli, F. Levi, A. Mura, M. Zucco, R. Ambrosini, C. Bortolotti, F. Perini, M. Roma, and D. Calonico, “A coherent fiber link for very long baseline interferometry,” IEEE Trans. Ultrason. Ferroelectr. Freq. Control 62, 1907–1912 (2015).
[Crossref]

Audoin, C.

C. Audoin, V. Candelier, and N. Dimarcq, “A limit to the frequency stability of passive frequency standards due to an intermodulation effect,” IEEE Trans. Instrum. Meas. 40, 121–125 (1991).
[Crossref]

Baehr-Jones, T.

Barbieri, P.

J. Grotti, S. Koller, S. Vogt, S. Häfner, U. Sterr, C. Lisdat, H. Denker, C. Voigt, L. Timmen, A. Rolland, F. N. Baynes, H. S. Margolis, M. Zampaolo, P. Thoumany, M. Pizzocaro, B. Rauf, F. Bregolin, A. Tampellini, P. Barbieri, M. Zucco, G. A. Costanzo, C. Clivati, F. Levi, and D. Calonico, “Geodesy and metrology with a transportable optical clock,” Nat. Phys. 14, 437–441 (2018).
[Crossref]

Bassini, M.

F. Biraben, M. Bassini, and B. Cagnac, “Line-shapes in Doppler-free two-photon spectroscopy the effect of finite transit time,” J. Phys. 40, 445–455 (1979).
[Crossref]

Baynes, F. N.

J. Grotti, S. Koller, S. Vogt, S. Häfner, U. Sterr, C. Lisdat, H. Denker, C. Voigt, L. Timmen, A. Rolland, F. N. Baynes, H. S. Margolis, M. Zampaolo, P. Thoumany, M. Pizzocaro, B. Rauf, F. Bregolin, A. Tampellini, P. Barbieri, M. Zucco, G. A. Costanzo, C. Clivati, F. Levi, and D. Calonico, “Geodesy and metrology with a transportable optical clock,” Nat. Phys. 14, 437–441 (2018).
[Crossref]

Beha, K.

P. Del’Haye, A. Coillet, T. Fortier, K. Beha, D. C. Cole, K. Y. Yang, H. Lee, K. J. Vahala, S. B. Papp, and S. A. Diddams, “Phase-coherent microwave-to-optical link with a self-referenced microcomb,” Nat. Photonics 10, 516–520 (2016).
[Crossref]

S. B. Papp, K. Beha, P. Del’Haye, F. Quinlan, H. Lee, K. J. Vahala, and S. A. Diddams, “Microresonator frequency comb optical clock,” Optica 1, 10–14 (2014).
[Crossref]

Behunin, R.

S. Gundavarapu, G. M. Brodnik, M. Puckett, T. Huffman, D. Bose, R. Behunin, J. Wu, T. Qiu, C. Pinho, N. Chauhan, J. Nohava, P. T. Rakich, K. D. Nelson, M. Salit, and D. J. Blumenthal, “Sub-hertz fundamental linewidth photonic integrated Brillouin laser,” Nat. Photonics 13, 60–67 (2018).
[Crossref]

Beloy, K.

M. Schioppo, R. C. Brown, W. F. McGrew, N. Hinkley, R. J. Fasano, K. Beloy, T. H. Yoon, G. Milani, D. Nicolodi, J. A. Sherman, N. B. Phillips, C. W. Oates, and A. D. Ludlow, “Ultrastable optical clock with two cold-atom ensembles,” Nat. Photonics 11, 48–52 (2016).
[Crossref]

Bergman, K.

Bergquist, J. C.

T. Rosenband, D. B. Hume, P. O. Schmidt, C. W. Chou, A. Brusch, L. Lorini, W. H. Oskay, R. E. Drullinger, T. M. Fortier, J. E. Stalnaker, S. A. Diddams, W. C. Swann, N. R. Newbury, W. M. Itano, D. J. Wineland, and J. C. Bergquist, “Frequency ratio of Al+ and Hg+ single-ion optical clocks; metrology at the 17th decimal place,” Science 319, 1808–1812 (2008).
[Crossref]

J. Ye, J.-L. Peng, R. J. Jones, K. W. Holman, J. L. Hall, D. J. Jones, S. A. Diddams, J. Kitching, S. Bize, J. C. Bergquist, L. W. Hollberg, L. Robertsson, and L.-S. Ma, “Delivery of high-stability optical and microwave frequency standards over an optical fiber network,” J. Opt. Soc. Am. B 20, 1459–1467 (2003).
[Crossref]

S. A. Diddams, T. Udem, J. C. Bergquist, E. A. Curtis, R. E. Drullinger, L. Hollberg, W. M. Itano, W. D. Lee, C. W. Oates, K. R. Vogel, and D. J. Wineland, “An optical clock based on a single trapped 199Hg+ ion,” Science 293, 825–828 (2001).
[Crossref]

Bernard, J. E.

J. E. Bernard, A. A. Madej, K. J. Siemsen, L. Marmet, C. Latrasse, D. Touahri, M. Poulin, M. Allard, and M. Tetu, “Absolute frequency measurement of a laser at 1556  nm locked to the 5S1/2-5D5/2 two-photon transition in 87-Rb,” Opt. Commun. 173, 357–364 (2000).
[Crossref]

Bigelow, M. S.

K. W. Martin, G. Phelps, N. D. Lemke, M. S. Bigelow, B. Stuhl, M. Wojcik, M. Holt, I. Coddington, M. W. Bishop, and J. H. Burke, “Compact optical atomic clock based on a two-photon transition in rubidium,” Phys. Rev. Appl. 9, 014019 (2018).
[Crossref]

Biraben, F.

L. Hilico, R. Felder, D. Touahri, O. Acef, A. Clairon, and F. Biraben, “Metrological features of the rubidium two-photon standards of the BNM-LPTF and Kastler Brossel Laboratories,” Eur. Phys. J. Appl. Phys. 4, 219–225 (1998).
[Crossref]

F. Biraben, M. Bassini, and B. Cagnac, “Line-shapes in Doppler-free two-photon spectroscopy the effect of finite transit time,” J. Phys. 40, 445–455 (1979).
[Crossref]

Bishop, M. W.

K. W. Martin, G. Phelps, N. D. Lemke, M. S. Bigelow, B. Stuhl, M. Wojcik, M. Holt, I. Coddington, M. W. Bishop, and J. H. Burke, “Compact optical atomic clock based on a two-photon transition in rubidium,” Phys. Rev. Appl. 9, 014019 (2018).
[Crossref]

Bize, S.

Bluestone, A.

D. T. Spencer, T. Drake, T. C. Briles, J. Stone, L. C. Sinclair, C. Fredrick, Q. Li, D. Westly, B. R. Ilic, A. Bluestone, N. Volet, T. Komljenovic, L. Chang, S. H. Lee, D. Y. Oh, M.-G. Suh, K. Y. Yang, M. H. P. Pfeiffer, T. J. Kippenberg, E. Norberg, L. Theogarajan, K. Vahala, N. R. Newbury, K. Srinivasan, J. E. Bowers, S. A. Diddams, and S. B. Papp, “An optical-frequency synthesizer using integrated photonics,” Nature 557, 81–85 (2018).
[Crossref]

Blumenthal, D. J.

S. Gundavarapu, G. M. Brodnik, M. Puckett, T. Huffman, D. Bose, R. Behunin, J. Wu, T. Qiu, C. Pinho, N. Chauhan, J. Nohava, P. T. Rakich, K. D. Nelson, M. Salit, and D. J. Blumenthal, “Sub-hertz fundamental linewidth photonic integrated Brillouin laser,” Nat. Photonics 13, 60–67 (2018).
[Crossref]

Bongs, K.

R. M. Godun, P. B. R. Nisbet-Jones, J. M. Jones, S. A. King, L. A. M. Johnson, H. S. Margolis, K. Szymaniec, S. N. Lea, K. Bongs, and P. Gill, “Frequency ratio of two optical clock transitions in 171Yb+ and constraints on the time variation of fundamental constants,” Phys. Rev. Lett. 113, 210801 (2014).
[Crossref]

Bopp, D. G.

Bortolotti, C.

C. Clivati, G. A. Costanzo, M. Frittelli, F. Levi, A. Mura, M. Zucco, R. Ambrosini, C. Bortolotti, F. Perini, M. Roma, and D. Calonico, “A coherent fiber link for very long baseline interferometry,” IEEE Trans. Ultrason. Ferroelectr. Freq. Control 62, 1907–1912 (2015).
[Crossref]

Bose, D.

S. Gundavarapu, G. M. Brodnik, M. Puckett, T. Huffman, D. Bose, R. Behunin, J. Wu, T. Qiu, C. Pinho, N. Chauhan, J. Nohava, P. T. Rakich, K. D. Nelson, M. Salit, and D. J. Blumenthal, “Sub-hertz fundamental linewidth photonic integrated Brillouin laser,” Nat. Photonics 13, 60–67 (2018).
[Crossref]

Bowers, J. E.

D. T. Spencer, T. Drake, T. C. Briles, J. Stone, L. C. Sinclair, C. Fredrick, Q. Li, D. Westly, B. R. Ilic, A. Bluestone, N. Volet, T. Komljenovic, L. Chang, S. H. Lee, D. Y. Oh, M.-G. Suh, K. Y. Yang, M. H. P. Pfeiffer, T. J. Kippenberg, E. Norberg, L. Theogarajan, K. Vahala, N. R. Newbury, K. Srinivasan, J. E. Bowers, S. A. Diddams, and S. B. Papp, “An optical-frequency synthesizer using integrated photonics,” Nature 557, 81–85 (2018).
[Crossref]

Brasch, V.

V. Brasch, E. Lucas, J. D. Jost, M. Geiselmann, and T. J. Kippenberg, “Self-referenced photonic chip soliton Kerr frequency comb,” Light: Sci. Appl. 6, e16202 (2017).
[Crossref]

J. D. Jost, T. Herr, C. Lecaplain, V. Brasch, M. H. P. Pfeiffer, and T. J. Kippenberg, “Counting the cycles of light using a self-referenced optical microresonator,” Optica 2, 706–711 (2015).
[Crossref]

T. Herr, V. Brasch, J. D. Jost, C. Y. Wang, N. M. Kondratiev, M. L. Gorodetsky, and T. J. Kippenberg, “Temporal solitons in optical microresonators,” Nat. Photonics 8, 145–152 (2013).
[Crossref]

Braxmaier, C.

Bregolin, F.

J. Grotti, S. Koller, S. Vogt, S. Häfner, U. Sterr, C. Lisdat, H. Denker, C. Voigt, L. Timmen, A. Rolland, F. N. Baynes, H. S. Margolis, M. Zampaolo, P. Thoumany, M. Pizzocaro, B. Rauf, F. Bregolin, A. Tampellini, P. Barbieri, M. Zucco, G. A. Costanzo, C. Clivati, F. Levi, and D. Calonico, “Geodesy and metrology with a transportable optical clock,” Nat. Phys. 14, 437–441 (2018).
[Crossref]

Briles, T. C.

D. T. Spencer, T. Drake, T. C. Briles, J. Stone, L. C. Sinclair, C. Fredrick, Q. Li, D. Westly, B. R. Ilic, A. Bluestone, N. Volet, T. Komljenovic, L. Chang, S. H. Lee, D. Y. Oh, M.-G. Suh, K. Y. Yang, M. H. P. Pfeiffer, T. J. Kippenberg, E. Norberg, L. Theogarajan, K. Vahala, N. R. Newbury, K. Srinivasan, J. E. Bowers, S. A. Diddams, and S. B. Papp, “An optical-frequency synthesizer using integrated photonics,” Nature 557, 81–85 (2018).
[Crossref]

T. C. Briles, J. R. Stone, T. E. Drake, D. T. Spencer, C. Frederick, Q. Li, D. A. Westly, B. R. Illic, K. Srinivasan, S. A. Diddams, and S. B. Papp, “Interlocking Kerr-microresonator frequency combs for microwave to optical synthesis,” Opt. Lett. 43, 2933–2936 (2018).
[Crossref]

J. R. Stone, T. C. Briles, T. E. Drake, D. T. Spencer, D. R. Carlson, S. A. Diddams, and S. B. Papp, “Thermal and nonlinear dissipative-soliton dynamics in Kerr-microresonator frequency combs,” Phys. Rev. Lett. 121, 63902 (2018).
[Crossref]

Q. Li, T. C. Briles, D. A. Westly, T. E. Drake, J. R. Stone, B. R. Ilic, S. A. Diddams, S. B. Papp, and K. Srinivasan, “Stably accessing octave-spanning microresonator frequency combs in the soliton regime,” Optica 4, 193–203 (2016).
[Crossref]

T. E. Drake, T. C. Briles, D. T. Spencer, J. R. Stone, D. R. Carlson, D. D. Hickstein, Q. Li, D. Westly, K. Srinivasan, S. A. Diddams, and S. B. Papp, “A Kerr-microresonator optical clockwork,” arXiv:1811.00581 (2018).

Brodnik, G. M.

S. Gundavarapu, G. M. Brodnik, M. Puckett, T. Huffman, D. Bose, R. Behunin, J. Wu, T. Qiu, C. Pinho, N. Chauhan, J. Nohava, P. T. Rakich, K. D. Nelson, M. Salit, and D. J. Blumenthal, “Sub-hertz fundamental linewidth photonic integrated Brillouin laser,” Nat. Photonics 13, 60–67 (2018).
[Crossref]

Brown, R. C.

M. Schioppo, R. C. Brown, W. F. McGrew, N. Hinkley, R. J. Fasano, K. Beloy, T. H. Yoon, G. Milani, D. Nicolodi, J. A. Sherman, N. B. Phillips, C. W. Oates, and A. D. Ludlow, “Ultrastable optical clock with two cold-atom ensembles,” Nat. Photonics 11, 48–52 (2016).
[Crossref]

Brusch, A.

T. Rosenband, D. B. Hume, P. O. Schmidt, C. W. Chou, A. Brusch, L. Lorini, W. H. Oskay, R. E. Drullinger, T. M. Fortier, J. E. Stalnaker, S. A. Diddams, W. C. Swann, N. R. Newbury, W. M. Itano, D. J. Wineland, and J. C. Bergquist, “Frequency ratio of Al+ and Hg+ single-ion optical clocks; metrology at the 17th decimal place,” Science 319, 1808–1812 (2008).
[Crossref]

Burke, J. H.

K. W. Martin, G. Phelps, N. D. Lemke, M. S. Bigelow, B. Stuhl, M. Wojcik, M. Holt, I. Coddington, M. W. Bishop, and J. H. Burke, “Compact optical atomic clock based on a two-photon transition in rubidium,” Phys. Rev. Appl. 9, 014019 (2018).
[Crossref]

N. D. Zameroski, G. D. Hager, C. J. Erickson, and J. H. Burke, “Pressure broadening and frequency shift of the 5S 1/2 to 5D 5/2 and 5S 1/2 to 7S 1/2 two photon transitions in 85Rb by the noble gases and N2,” J. Phys. B 47, 225205 (2014).
[Crossref]

Byrd, J.

Cagnac, B.

F. Biraben, M. Bassini, and B. Cagnac, “Line-shapes in Doppler-free two-photon spectroscopy the effect of finite transit time,” J. Phys. 40, 445–455 (1979).
[Crossref]

G. Grynberg and B. Cagnac, “Doppler-free multiphotonic spectroscopy,” Rep. Prog. Phys. 40, 791–841 (1977).
[Crossref]

Calonico, D.

J. Grotti, S. Koller, S. Vogt, S. Häfner, U. Sterr, C. Lisdat, H. Denker, C. Voigt, L. Timmen, A. Rolland, F. N. Baynes, H. S. Margolis, M. Zampaolo, P. Thoumany, M. Pizzocaro, B. Rauf, F. Bregolin, A. Tampellini, P. Barbieri, M. Zucco, G. A. Costanzo, C. Clivati, F. Levi, and D. Calonico, “Geodesy and metrology with a transportable optical clock,” Nat. Phys. 14, 437–441 (2018).
[Crossref]

C. Clivati, G. A. Costanzo, M. Frittelli, F. Levi, A. Mura, M. Zucco, R. Ambrosini, C. Bortolotti, F. Perini, M. Roma, and D. Calonico, “A coherent fiber link for very long baseline interferometry,” IEEE Trans. Ultrason. Ferroelectr. Freq. Control 62, 1907–1912 (2015).
[Crossref]

Candelier, V.

C. Audoin, V. Candelier, and N. Dimarcq, “A limit to the frequency stability of passive frequency standards due to an intermodulation effect,” IEEE Trans. Instrum. Meas. 40, 121–125 (1991).
[Crossref]

Carlson, D. R.

J. R. Stone, T. C. Briles, T. E. Drake, D. T. Spencer, D. R. Carlson, S. A. Diddams, and S. B. Papp, “Thermal and nonlinear dissipative-soliton dynamics in Kerr-microresonator frequency combs,” Phys. Rev. Lett. 121, 63902 (2018).
[Crossref]

T. E. Drake, T. C. Briles, D. T. Spencer, J. R. Stone, D. R. Carlson, D. D. Hickstein, Q. Li, D. Westly, K. Srinivasan, S. A. Diddams, and S. B. Papp, “A Kerr-microresonator optical clockwork,” arXiv:1811.00581 (2018).

Caverley, M.

Chang, L.

D. T. Spencer, T. Drake, T. C. Briles, J. Stone, L. C. Sinclair, C. Fredrick, Q. Li, D. Westly, B. R. Ilic, A. Bluestone, N. Volet, T. Komljenovic, L. Chang, S. H. Lee, D. Y. Oh, M.-G. Suh, K. Y. Yang, M. H. P. Pfeiffer, T. J. Kippenberg, E. Norberg, L. Theogarajan, K. Vahala, N. R. Newbury, K. Srinivasan, J. E. Bowers, S. A. Diddams, and S. B. Papp, “An optical-frequency synthesizer using integrated photonics,” Nature 557, 81–85 (2018).
[Crossref]

Chauhan, N.

S. Gundavarapu, G. M. Brodnik, M. Puckett, T. Huffman, D. Bose, R. Behunin, J. Wu, T. Qiu, C. Pinho, N. Chauhan, J. Nohava, P. T. Rakich, K. D. Nelson, M. Salit, and D. J. Blumenthal, “Sub-hertz fundamental linewidth photonic integrated Brillouin laser,” Nat. Photonics 13, 60–67 (2018).
[Crossref]

Chou, C. W.

T. Rosenband, D. B. Hume, P. O. Schmidt, C. W. Chou, A. Brusch, L. Lorini, W. H. Oskay, R. E. Drullinger, T. M. Fortier, J. E. Stalnaker, S. A. Diddams, W. C. Swann, N. R. Newbury, W. M. Itano, D. J. Wineland, and J. C. Bergquist, “Frequency ratio of Al+ and Hg+ single-ion optical clocks; metrology at the 17th decimal place,” Science 319, 1808–1812 (2008).
[Crossref]

Clairon, A.

L. Hilico, R. Felder, D. Touahri, O. Acef, A. Clairon, and F. Biraben, “Metrological features of the rubidium two-photon standards of the BNM-LPTF and Kastler Brossel Laboratories,” Eur. Phys. J. Appl. Phys. 4, 219–225 (1998).
[Crossref]

Clivati, C.

J. Grotti, S. Koller, S. Vogt, S. Häfner, U. Sterr, C. Lisdat, H. Denker, C. Voigt, L. Timmen, A. Rolland, F. N. Baynes, H. S. Margolis, M. Zampaolo, P. Thoumany, M. Pizzocaro, B. Rauf, F. Bregolin, A. Tampellini, P. Barbieri, M. Zucco, G. A. Costanzo, C. Clivati, F. Levi, and D. Calonico, “Geodesy and metrology with a transportable optical clock,” Nat. Phys. 14, 437–441 (2018).
[Crossref]

C. Clivati, G. A. Costanzo, M. Frittelli, F. Levi, A. Mura, M. Zucco, R. Ambrosini, C. Bortolotti, F. Perini, M. Roma, and D. Calonico, “A coherent fiber link for very long baseline interferometry,” IEEE Trans. Ultrason. Ferroelectr. Freq. Control 62, 1907–1912 (2015).
[Crossref]

Coddington, I.

K. W. Martin, G. Phelps, N. D. Lemke, M. S. Bigelow, B. Stuhl, M. Wojcik, M. Holt, I. Coddington, M. W. Bishop, and J. H. Burke, “Compact optical atomic clock based on a two-photon transition in rubidium,” Phys. Rev. Appl. 9, 014019 (2018).
[Crossref]

Coen, S.

Coillet, A.

P. Del’Haye, A. Coillet, T. Fortier, K. Beha, D. C. Cole, K. Y. Yang, H. Lee, K. J. Vahala, S. B. Papp, and S. A. Diddams, “Phase-coherent microwave-to-optical link with a self-referenced microcomb,” Nat. Photonics 10, 516–520 (2016).
[Crossref]

Cole, D. C.

P. Del’Haye, A. Coillet, T. Fortier, K. Beha, D. C. Cole, K. Y. Yang, H. Lee, K. J. Vahala, S. B. Papp, and S. A. Diddams, “Phase-coherent microwave-to-optical link with a self-referenced microcomb,” Nat. Photonics 10, 516–520 (2016).
[Crossref]

Costanzo, G. A.

J. Grotti, S. Koller, S. Vogt, S. Häfner, U. Sterr, C. Lisdat, H. Denker, C. Voigt, L. Timmen, A. Rolland, F. N. Baynes, H. S. Margolis, M. Zampaolo, P. Thoumany, M. Pizzocaro, B. Rauf, F. Bregolin, A. Tampellini, P. Barbieri, M. Zucco, G. A. Costanzo, C. Clivati, F. Levi, and D. Calonico, “Geodesy and metrology with a transportable optical clock,” Nat. Phys. 14, 437–441 (2018).
[Crossref]

C. Clivati, G. A. Costanzo, M. Frittelli, F. Levi, A. Mura, M. Zucco, R. Ambrosini, C. Bortolotti, F. Perini, M. Roma, and D. Calonico, “A coherent fiber link for very long baseline interferometry,” IEEE Trans. Ultrason. Ferroelectr. Freq. Control 62, 1907–1912 (2015).
[Crossref]

Cundiff, S. T.

D. J. Jones, S. A. Diddams, J. K. Ranka, A. Stentz, R. S. Windeler, J. L. Hall, and S. T. Cundiff, “Carrier-envelope phase control of femtosecond mode-locked lasers and direct optical frequency synthesis,” Science 288, 635–639 (2000).
[Crossref]

Curtis, E. A.

S. A. Diddams, T. Udem, J. C. Bergquist, E. A. Curtis, R. E. Drullinger, L. Hollberg, W. M. Itano, W. D. Lee, C. W. Oates, K. R. Vogel, and D. J. Wineland, “An optical clock based on a single trapped 199Hg+ ion,” Science 293, 825–828 (2001).
[Crossref]

Del’Haye, P.

P. Del’Haye, A. Coillet, T. Fortier, K. Beha, D. C. Cole, K. Y. Yang, H. Lee, K. J. Vahala, S. B. Papp, and S. A. Diddams, “Phase-coherent microwave-to-optical link with a self-referenced microcomb,” Nat. Photonics 10, 516–520 (2016).
[Crossref]

S. B. Papp, K. Beha, P. Del’Haye, F. Quinlan, H. Lee, K. J. Vahala, and S. A. Diddams, “Microresonator frequency comb optical clock,” Optica 1, 10–14 (2014).
[Crossref]

Denker, H.

J. Grotti, S. Koller, S. Vogt, S. Häfner, U. Sterr, C. Lisdat, H. Denker, C. Voigt, L. Timmen, A. Rolland, F. N. Baynes, H. S. Margolis, M. Zampaolo, P. Thoumany, M. Pizzocaro, B. Rauf, F. Bregolin, A. Tampellini, P. Barbieri, M. Zucco, G. A. Costanzo, C. Clivati, F. Levi, and D. Calonico, “Geodesy and metrology with a transportable optical clock,” Nat. Phys. 14, 437–441 (2018).
[Crossref]

Diddams, S. A.

M. T. Hummon, S. Kang, D. G. Bopp, Q. Li, D. A. Westly, S. Kim, C. Fredrick, S. A. Diddams, K. Srinivasan, V. Aksyuk, and J. E. Kitching, “Photonic chip for laser stabilization to an atomic vapor with 10-11 instability,” Optica 5, 443–449 (2018).
[Crossref]

D. T. Spencer, T. Drake, T. C. Briles, J. Stone, L. C. Sinclair, C. Fredrick, Q. Li, D. Westly, B. R. Ilic, A. Bluestone, N. Volet, T. Komljenovic, L. Chang, S. H. Lee, D. Y. Oh, M.-G. Suh, K. Y. Yang, M. H. P. Pfeiffer, T. J. Kippenberg, E. Norberg, L. Theogarajan, K. Vahala, N. R. Newbury, K. Srinivasan, J. E. Bowers, S. A. Diddams, and S. B. Papp, “An optical-frequency synthesizer using integrated photonics,” Nature 557, 81–85 (2018).
[Crossref]

T. C. Briles, J. R. Stone, T. E. Drake, D. T. Spencer, C. Frederick, Q. Li, D. A. Westly, B. R. Illic, K. Srinivasan, S. A. Diddams, and S. B. Papp, “Interlocking Kerr-microresonator frequency combs for microwave to optical synthesis,” Opt. Lett. 43, 2933–2936 (2018).
[Crossref]

J. R. Stone, T. C. Briles, T. E. Drake, D. T. Spencer, D. R. Carlson, S. A. Diddams, and S. B. Papp, “Thermal and nonlinear dissipative-soliton dynamics in Kerr-microresonator frequency combs,” Phys. Rev. Lett. 121, 63902 (2018).
[Crossref]

P. Del’Haye, A. Coillet, T. Fortier, K. Beha, D. C. Cole, K. Y. Yang, H. Lee, K. J. Vahala, S. B. Papp, and S. A. Diddams, “Phase-coherent microwave-to-optical link with a self-referenced microcomb,” Nat. Photonics 10, 516–520 (2016).
[Crossref]

Q. Li, T. C. Briles, D. A. Westly, T. E. Drake, J. R. Stone, B. R. Ilic, S. A. Diddams, S. B. Papp, and K. Srinivasan, “Stably accessing octave-spanning microresonator frequency combs in the soliton regime,” Optica 4, 193–203 (2016).
[Crossref]

S. B. Papp, K. Beha, P. Del’Haye, F. Quinlan, H. Lee, K. J. Vahala, and S. A. Diddams, “Microresonator frequency comb optical clock,” Optica 1, 10–14 (2014).
[Crossref]

T. Rosenband, D. B. Hume, P. O. Schmidt, C. W. Chou, A. Brusch, L. Lorini, W. H. Oskay, R. E. Drullinger, T. M. Fortier, J. E. Stalnaker, S. A. Diddams, W. C. Swann, N. R. Newbury, W. M. Itano, D. J. Wineland, and J. C. Bergquist, “Frequency ratio of Al+ and Hg+ single-ion optical clocks; metrology at the 17th decimal place,” Science 319, 1808–1812 (2008).
[Crossref]

J. Ye, J.-L. Peng, R. J. Jones, K. W. Holman, J. L. Hall, D. J. Jones, S. A. Diddams, J. Kitching, S. Bize, J. C. Bergquist, L. W. Hollberg, L. Robertsson, and L.-S. Ma, “Delivery of high-stability optical and microwave frequency standards over an optical fiber network,” J. Opt. Soc. Am. B 20, 1459–1467 (2003).
[Crossref]

S. A. Diddams, T. Udem, J. C. Bergquist, E. A. Curtis, R. E. Drullinger, L. Hollberg, W. M. Itano, W. D. Lee, C. W. Oates, K. R. Vogel, and D. J. Wineland, “An optical clock based on a single trapped 199Hg+ ion,” Science 293, 825–828 (2001).
[Crossref]

D. J. Jones, S. A. Diddams, J. K. Ranka, A. Stentz, R. S. Windeler, J. L. Hall, and S. T. Cundiff, “Carrier-envelope phase control of femtosecond mode-locked lasers and direct optical frequency synthesis,” Science 288, 635–639 (2000).
[Crossref]

T. E. Drake, T. C. Briles, D. T. Spencer, J. R. Stone, D. R. Carlson, D. D. Hickstein, Q. Li, D. Westly, K. Srinivasan, S. A. Diddams, and S. B. Papp, “A Kerr-microresonator optical clockwork,” arXiv:1811.00581 (2018).

Dimarcq, N.

C. Audoin, V. Candelier, and N. Dimarcq, “A limit to the frequency stability of passive frequency standards due to an intermodulation effect,” IEEE Trans. Instrum. Meas. 40, 121–125 (1991).
[Crossref]

Döringshoff, K.

Dörscher, S.

S. B. Koller, J. Grotti, S. Vogt, A. Al-Masoudi, S. Dörscher, S. Häfner, U. Sterr, and C. Lisdat, “Transportable optical lattice clock with 7×10-17 uncertainty,” Phys. Rev. Lett. 118, 073601 (2017).
[Crossref]

Drake, T.

D. T. Spencer, T. Drake, T. C. Briles, J. Stone, L. C. Sinclair, C. Fredrick, Q. Li, D. Westly, B. R. Ilic, A. Bluestone, N. Volet, T. Komljenovic, L. Chang, S. H. Lee, D. Y. Oh, M.-G. Suh, K. Y. Yang, M. H. P. Pfeiffer, T. J. Kippenberg, E. Norberg, L. Theogarajan, K. Vahala, N. R. Newbury, K. Srinivasan, J. E. Bowers, S. A. Diddams, and S. B. Papp, “An optical-frequency synthesizer using integrated photonics,” Nature 557, 81–85 (2018).
[Crossref]

Drake, T. E.

T. C. Briles, J. R. Stone, T. E. Drake, D. T. Spencer, C. Frederick, Q. Li, D. A. Westly, B. R. Illic, K. Srinivasan, S. A. Diddams, and S. B. Papp, “Interlocking Kerr-microresonator frequency combs for microwave to optical synthesis,” Opt. Lett. 43, 2933–2936 (2018).
[Crossref]

J. R. Stone, T. C. Briles, T. E. Drake, D. T. Spencer, D. R. Carlson, S. A. Diddams, and S. B. Papp, “Thermal and nonlinear dissipative-soliton dynamics in Kerr-microresonator frequency combs,” Phys. Rev. Lett. 121, 63902 (2018).
[Crossref]

Q. Li, T. C. Briles, D. A. Westly, T. E. Drake, J. R. Stone, B. R. Ilic, S. A. Diddams, S. B. Papp, and K. Srinivasan, “Stably accessing octave-spanning microresonator frequency combs in the soliton regime,” Optica 4, 193–203 (2016).
[Crossref]

T. E. Drake, T. C. Briles, D. T. Spencer, J. R. Stone, D. R. Carlson, D. D. Hickstein, Q. Li, D. Westly, K. Srinivasan, S. A. Diddams, and S. B. Papp, “A Kerr-microresonator optical clockwork,” arXiv:1811.00581 (2018).

Drullinger, R. E.

T. Rosenband, D. B. Hume, P. O. Schmidt, C. W. Chou, A. Brusch, L. Lorini, W. H. Oskay, R. E. Drullinger, T. M. Fortier, J. E. Stalnaker, S. A. Diddams, W. C. Swann, N. R. Newbury, W. M. Itano, D. J. Wineland, and J. C. Bergquist, “Frequency ratio of Al+ and Hg+ single-ion optical clocks; metrology at the 17th decimal place,” Science 319, 1808–1812 (2008).
[Crossref]

S. A. Diddams, T. Udem, J. C. Bergquist, E. A. Curtis, R. E. Drullinger, L. Hollberg, W. M. Itano, W. D. Lee, C. W. Oates, K. R. Vogel, and D. J. Wineland, “An optical clock based on a single trapped 199Hg+ ion,” Science 293, 825–828 (2001).
[Crossref]

Eliyahu, D.

W. Liang, D. Eliyahu, V. S. Ilchenko, A. A. Savchenkov, D. Seidel, L. Maleki, and A. B. Matsko, “High spectral purity Kerr frequency comb radio frequency photonic oscillator,” Nat. Commun. 6, 1–8 (2015).
[Crossref]

A. A. Savchenkov, D. Eliyahu, W. Liang, V. S. Ilchenko, J. Byrd, A. B. Matsko, D. Seidel, and L. Maleki, “Stabilization of a Kerr frequency comb oscillator,” Opt. Lett. 38, 2636–2639 (2013).
[Crossref]

Engelsen, N. J.

J. Liu, A. S. Raja, M. Karpov, B. Ghadiani, M. H. P. Pfeiffer, N. J. Engelsen, H. Guo, M. Zervas, and T. J. Kippenberg, “Ultralow-power chip-based soliton microcombs for photonic integration,” Optica 5, 3–9 (2018).
[Crossref]

Erickson, C. J.

N. D. Zameroski, G. D. Hager, C. J. Erickson, and J. H. Burke, “Pressure broadening and frequency shift of the 5S 1/2 to 5D 5/2 and 5S 1/2 to 7S 1/2 two photon transitions in 85Rb by the noble gases and N2,” J. Phys. B 47, 225205 (2014).
[Crossref]

Erkintalo, M.

Fasano, R. J.

M. Schioppo, R. C. Brown, W. F. McGrew, N. Hinkley, R. J. Fasano, K. Beloy, T. H. Yoon, G. Milani, D. Nicolodi, J. A. Sherman, N. B. Phillips, C. W. Oates, and A. D. Ludlow, “Ultrastable optical clock with two cold-atom ensembles,” Nat. Photonics 11, 48–52 (2016).
[Crossref]

Fathololoumi, S.

Felder, R.

L. Hilico, R. Felder, D. Touahri, O. Acef, A. Clairon, and F. Biraben, “Metrological features of the rubidium two-photon standards of the BNM-LPTF and Kastler Brossel Laboratories,” Eur. Phys. J. Appl. Phys. 4, 219–225 (1998).
[Crossref]

Fortier, T.

P. Del’Haye, A. Coillet, T. Fortier, K. Beha, D. C. Cole, K. Y. Yang, H. Lee, K. J. Vahala, S. B. Papp, and S. A. Diddams, “Phase-coherent microwave-to-optical link with a self-referenced microcomb,” Nat. Photonics 10, 516–520 (2016).
[Crossref]

Fortier, T. M.

T. Rosenband, D. B. Hume, P. O. Schmidt, C. W. Chou, A. Brusch, L. Lorini, W. H. Oskay, R. E. Drullinger, T. M. Fortier, J. E. Stalnaker, S. A. Diddams, W. C. Swann, N. R. Newbury, W. M. Itano, D. J. Wineland, and J. C. Bergquist, “Frequency ratio of Al+ and Hg+ single-ion optical clocks; metrology at the 17th decimal place,” Science 319, 1808–1812 (2008).
[Crossref]

Frederick, C.

Fredrick, C.

D. T. Spencer, T. Drake, T. C. Briles, J. Stone, L. C. Sinclair, C. Fredrick, Q. Li, D. Westly, B. R. Ilic, A. Bluestone, N. Volet, T. Komljenovic, L. Chang, S. H. Lee, D. Y. Oh, M.-G. Suh, K. Y. Yang, M. H. P. Pfeiffer, T. J. Kippenberg, E. Norberg, L. Theogarajan, K. Vahala, N. R. Newbury, K. Srinivasan, J. E. Bowers, S. A. Diddams, and S. B. Papp, “An optical-frequency synthesizer using integrated photonics,” Nature 557, 81–85 (2018).
[Crossref]

M. T. Hummon, S. Kang, D. G. Bopp, Q. Li, D. A. Westly, S. Kim, C. Fredrick, S. A. Diddams, K. Srinivasan, V. Aksyuk, and J. E. Kitching, “Photonic chip for laser stabilization to an atomic vapor with 10-11 instability,” Optica 5, 443–449 (2018).
[Crossref]

Frittelli, M.

C. Clivati, G. A. Costanzo, M. Frittelli, F. Levi, A. Mura, M. Zucco, R. Ambrosini, C. Bortolotti, F. Perini, M. Roma, and D. Calonico, “A coherent fiber link for very long baseline interferometry,” IEEE Trans. Ultrason. Ferroelectr. Freq. Control 62, 1907–1912 (2015).
[Crossref]

Gaeta, A. L.

B. Stern, X. Ji, Y. Okawachi, A. L. Gaeta, and M. Lipson, “Battery-operated integrated frequency comb generator,” Nature 562, 401–405 (2018).
[Crossref]

T. J. Kippenberg, A. L. Gaeta, M. Lipson, and M. L. Gorodetsky, “Dissipative Kerr solitons in optical microresonators,” Science 361, eaan8083 (2018).
[Crossref]

Galfsky, T.

Geiselmann, M.

V. Brasch, E. Lucas, J. D. Jost, M. Geiselmann, and T. J. Kippenberg, “Self-referenced photonic chip soliton Kerr frequency comb,” Light: Sci. Appl. 6, e16202 (2017).
[Crossref]

Ghadiani, B.

J. Liu, A. S. Raja, M. Karpov, B. Ghadiani, M. H. P. Pfeiffer, N. J. Engelsen, H. Guo, M. Zervas, and T. J. Kippenberg, “Ultralow-power chip-based soliton microcombs for photonic integration,” Optica 5, 3–9 (2018).
[Crossref]

Gill, P.

R. M. Godun, P. B. R. Nisbet-Jones, J. M. Jones, S. A. King, L. A. M. Johnson, H. S. Margolis, K. Szymaniec, S. N. Lea, K. Bongs, and P. Gill, “Frequency ratio of two optical clock transitions in 171Yb+ and constraints on the time variation of fundamental constants,” Phys. Rev. Lett. 113, 210801 (2014).
[Crossref]

Godun, R. M.

R. M. Godun, P. B. R. Nisbet-Jones, J. M. Jones, S. A. King, L. A. M. Johnson, H. S. Margolis, K. Szymaniec, S. N. Lea, K. Bongs, and P. Gill, “Frequency ratio of two optical clock transitions in 171Yb+ and constraints on the time variation of fundamental constants,” Phys. Rev. Lett. 113, 210801 (2014).
[Crossref]

Gorodetsky, M. L.

T. J. Kippenberg, A. L. Gaeta, M. Lipson, and M. L. Gorodetsky, “Dissipative Kerr solitons in optical microresonators,” Science 361, eaan8083 (2018).
[Crossref]

T. Herr, V. Brasch, J. D. Jost, C. Y. Wang, N. M. Kondratiev, M. L. Gorodetsky, and T. J. Kippenberg, “Temporal solitons in optical microresonators,” Nat. Photonics 8, 145–152 (2013).
[Crossref]

Grotti, J.

J. Grotti, S. Koller, S. Vogt, S. Häfner, U. Sterr, C. Lisdat, H. Denker, C. Voigt, L. Timmen, A. Rolland, F. N. Baynes, H. S. Margolis, M. Zampaolo, P. Thoumany, M. Pizzocaro, B. Rauf, F. Bregolin, A. Tampellini, P. Barbieri, M. Zucco, G. A. Costanzo, C. Clivati, F. Levi, and D. Calonico, “Geodesy and metrology with a transportable optical clock,” Nat. Phys. 14, 437–441 (2018).
[Crossref]

S. B. Koller, J. Grotti, S. Vogt, A. Al-Masoudi, S. Dörscher, S. Häfner, U. Sterr, and C. Lisdat, “Transportable optical lattice clock with 7×10-17 uncertainty,” Phys. Rev. Lett. 118, 073601 (2017).
[Crossref]

Grynberg, G.

G. Grynberg and B. Cagnac, “Doppler-free multiphotonic spectroscopy,” Rep. Prog. Phys. 40, 791–841 (1977).
[Crossref]

Guan, H.

Gundavarapu, S.

S. Gundavarapu, G. M. Brodnik, M. Puckett, T. Huffman, D. Bose, R. Behunin, J. Wu, T. Qiu, C. Pinho, N. Chauhan, J. Nohava, P. T. Rakich, K. D. Nelson, M. Salit, and D. J. Blumenthal, “Sub-hertz fundamental linewidth photonic integrated Brillouin laser,” Nat. Photonics 13, 60–67 (2018).
[Crossref]

Guo, H.

J. Liu, A. S. Raja, M. Karpov, B. Ghadiani, M. H. P. Pfeiffer, N. J. Engelsen, H. Guo, M. Zervas, and T. J. Kippenberg, “Ultralow-power chip-based soliton microcombs for photonic integration,” Optica 5, 3–9 (2018).
[Crossref]

M. H. P. Pfeiffer, C. Herkommer, J. Liu, H. Guo, M. Karpov, E. Lucas, M. Zervas, and T. J. Kippenberg, “Octave-spanning dissipative Kerr soliton frequency combs in Si3N4 microresonators,” Optica 4, 684–690 (2017).
[Crossref]

Guo, X.

Häfner, S.

J. Grotti, S. Koller, S. Vogt, S. Häfner, U. Sterr, C. Lisdat, H. Denker, C. Voigt, L. Timmen, A. Rolland, F. N. Baynes, H. S. Margolis, M. Zampaolo, P. Thoumany, M. Pizzocaro, B. Rauf, F. Bregolin, A. Tampellini, P. Barbieri, M. Zucco, G. A. Costanzo, C. Clivati, F. Levi, and D. Calonico, “Geodesy and metrology with a transportable optical clock,” Nat. Phys. 14, 437–441 (2018).
[Crossref]

S. B. Koller, J. Grotti, S. Vogt, A. Al-Masoudi, S. Dörscher, S. Häfner, U. Sterr, and C. Lisdat, “Transportable optical lattice clock with 7×10-17 uncertainty,” Phys. Rev. Lett. 118, 073601 (2017).
[Crossref]

Hager, G. D.

N. D. Zameroski, G. D. Hager, C. J. Erickson, and J. H. Burke, “Pressure broadening and frequency shift of the 5S 1/2 to 5D 5/2 and 5S 1/2 to 7S 1/2 two photon transitions in 85Rb by the noble gases and N2,” J. Phys. B 47, 225205 (2014).
[Crossref]

Hall, J. L.

J. Ye, J.-L. Peng, R. J. Jones, K. W. Holman, J. L. Hall, D. J. Jones, S. A. Diddams, J. Kitching, S. Bize, J. C. Bergquist, L. W. Hollberg, L. Robertsson, and L.-S. Ma, “Delivery of high-stability optical and microwave frequency standards over an optical fiber network,” J. Opt. Soc. Am. B 20, 1459–1467 (2003).
[Crossref]

D. J. Jones, S. A. Diddams, J. K. Ranka, A. Stentz, R. S. Windeler, J. L. Hall, and S. T. Cundiff, “Carrier-envelope phase control of femtosecond mode-locked lasers and direct optical frequency synthesis,” Science 288, 635–639 (2000).
[Crossref]

Herkommer, C.

Herr, T.

J. D. Jost, T. Herr, C. Lecaplain, V. Brasch, M. H. P. Pfeiffer, and T. J. Kippenberg, “Counting the cycles of light using a self-referenced optical microresonator,” Optica 2, 706–711 (2015).
[Crossref]

T. Herr, V. Brasch, J. D. Jost, C. Y. Wang, N. M. Kondratiev, M. L. Gorodetsky, and T. J. Kippenberg, “Temporal solitons in optical microresonators,” Nat. Photonics 8, 145–152 (2013).
[Crossref]

Hickstein, D. D.

T. E. Drake, T. C. Briles, D. T. Spencer, J. R. Stone, D. R. Carlson, D. D. Hickstein, Q. Li, D. Westly, K. Srinivasan, S. A. Diddams, and S. B. Papp, “A Kerr-microresonator optical clockwork,” arXiv:1811.00581 (2018).

Hilico, L.

L. Hilico, R. Felder, D. Touahri, O. Acef, A. Clairon, and F. Biraben, “Metrological features of the rubidium two-photon standards of the BNM-LPTF and Kastler Brossel Laboratories,” Eur. Phys. J. Appl. Phys. 4, 219–225 (1998).
[Crossref]

Hinkley, N.

M. Schioppo, R. C. Brown, W. F. McGrew, N. Hinkley, R. J. Fasano, K. Beloy, T. H. Yoon, G. Milani, D. Nicolodi, J. A. Sherman, N. B. Phillips, C. W. Oates, and A. D. Ludlow, “Ultrastable optical clock with two cold-atom ensembles,” Nat. Photonics 11, 48–52 (2016).
[Crossref]

Hochberg, M.

Hollberg, L.

S. Knappe, V. Shah, P. D. D. Schwindt, L. Hollberg, J. Kitching, L. A. Liew, and J. Moreland, “A microfabricated atomic clock,” Appl. Phys. Lett. 85, 1460–1462 (2004).
[Crossref]

S. A. Diddams, T. Udem, J. C. Bergquist, E. A. Curtis, R. E. Drullinger, L. Hollberg, W. M. Itano, W. D. Lee, C. W. Oates, K. R. Vogel, and D. J. Wineland, “An optical clock based on a single trapped 199Hg+ ion,” Science 293, 825–828 (2001).
[Crossref]

Hollberg, L. W.

Holman, K. W.

Holt, M.

K. W. Martin, G. Phelps, N. D. Lemke, M. S. Bigelow, B. Stuhl, M. Wojcik, M. Holt, I. Coddington, M. W. Bishop, and J. H. Burke, “Compact optical atomic clock based on a two-photon transition in rubidium,” Phys. Rev. Appl. 9, 014019 (2018).
[Crossref]

Horth, A.

Huffman, T.

S. Gundavarapu, G. M. Brodnik, M. Puckett, T. Huffman, D. Bose, R. Behunin, J. Wu, T. Qiu, C. Pinho, N. Chauhan, J. Nohava, P. T. Rakich, K. D. Nelson, M. Salit, and D. J. Blumenthal, “Sub-hertz fundamental linewidth photonic integrated Brillouin laser,” Nat. Photonics 13, 60–67 (2018).
[Crossref]

Hume, D. B.

T. Rosenband, D. B. Hume, P. O. Schmidt, C. W. Chou, A. Brusch, L. Lorini, W. H. Oskay, R. E. Drullinger, T. M. Fortier, J. E. Stalnaker, S. A. Diddams, W. C. Swann, N. R. Newbury, W. M. Itano, D. J. Wineland, and J. C. Bergquist, “Frequency ratio of Al+ and Hg+ single-ion optical clocks; metrology at the 17th decimal place,” Science 319, 1808–1812 (2008).
[Crossref]

Hummon, M. T.

Huynh, T.

Ilchenko, V. S.

W. Liang, D. Eliyahu, V. S. Ilchenko, A. A. Savchenkov, D. Seidel, L. Maleki, and A. B. Matsko, “High spectral purity Kerr frequency comb radio frequency photonic oscillator,” Nat. Commun. 6, 1–8 (2015).
[Crossref]

A. A. Savchenkov, D. Eliyahu, W. Liang, V. S. Ilchenko, J. Byrd, A. B. Matsko, D. Seidel, and L. Maleki, “Stabilization of a Kerr frequency comb oscillator,” Opt. Lett. 38, 2636–2639 (2013).
[Crossref]

Ilic, B. R.

D. T. Spencer, T. Drake, T. C. Briles, J. Stone, L. C. Sinclair, C. Fredrick, Q. Li, D. Westly, B. R. Ilic, A. Bluestone, N. Volet, T. Komljenovic, L. Chang, S. H. Lee, D. Y. Oh, M.-G. Suh, K. Y. Yang, M. H. P. Pfeiffer, T. J. Kippenberg, E. Norberg, L. Theogarajan, K. Vahala, N. R. Newbury, K. Srinivasan, J. E. Bowers, S. A. Diddams, and S. B. Papp, “An optical-frequency synthesizer using integrated photonics,” Nature 557, 81–85 (2018).
[Crossref]

Q. Li, T. C. Briles, D. A. Westly, T. E. Drake, J. R. Stone, B. R. Ilic, S. A. Diddams, S. B. Papp, and K. Srinivasan, “Stably accessing octave-spanning microresonator frequency combs in the soliton regime,” Optica 4, 193–203 (2016).
[Crossref]

Illic, B. R.

Itano, W. M.

T. Rosenband, D. B. Hume, P. O. Schmidt, C. W. Chou, A. Brusch, L. Lorini, W. H. Oskay, R. E. Drullinger, T. M. Fortier, J. E. Stalnaker, S. A. Diddams, W. C. Swann, N. R. Newbury, W. M. Itano, D. J. Wineland, and J. C. Bergquist, “Frequency ratio of Al+ and Hg+ single-ion optical clocks; metrology at the 17th decimal place,” Science 319, 1808–1812 (2008).
[Crossref]

S. A. Diddams, T. Udem, J. C. Bergquist, E. A. Curtis, R. E. Drullinger, L. Hollberg, W. M. Itano, W. D. Lee, C. W. Oates, K. R. Vogel, and D. J. Wineland, “An optical clock based on a single trapped 199Hg+ ion,” Science 293, 825–828 (2001).
[Crossref]

Ji, X.

B. Stern, X. Ji, Y. Okawachi, A. L. Gaeta, and M. Lipson, “Battery-operated integrated frequency comb generator,” Nature 562, 401–405 (2018).
[Crossref]

Johnson, L. A. M.

R. M. Godun, P. B. R. Nisbet-Jones, J. M. Jones, S. A. King, L. A. M. Johnson, H. S. Margolis, K. Szymaniec, S. N. Lea, K. Bongs, and P. Gill, “Frequency ratio of two optical clock transitions in 171Yb+ and constraints on the time variation of fundamental constants,” Phys. Rev. Lett. 113, 210801 (2014).
[Crossref]

Jones, D. J.

J. Ye, J.-L. Peng, R. J. Jones, K. W. Holman, J. L. Hall, D. J. Jones, S. A. Diddams, J. Kitching, S. Bize, J. C. Bergquist, L. W. Hollberg, L. Robertsson, and L.-S. Ma, “Delivery of high-stability optical and microwave frequency standards over an optical fiber network,” J. Opt. Soc. Am. B 20, 1459–1467 (2003).
[Crossref]

D. J. Jones, S. A. Diddams, J. K. Ranka, A. Stentz, R. S. Windeler, J. L. Hall, and S. T. Cundiff, “Carrier-envelope phase control of femtosecond mode-locked lasers and direct optical frequency synthesis,” Science 288, 635–639 (2000).
[Crossref]

Jones, J. M.

R. M. Godun, P. B. R. Nisbet-Jones, J. M. Jones, S. A. King, L. A. M. Johnson, H. S. Margolis, K. Szymaniec, S. N. Lea, K. Bongs, and P. Gill, “Frequency ratio of two optical clock transitions in 171Yb+ and constraints on the time variation of fundamental constants,” Phys. Rev. Lett. 113, 210801 (2014).
[Crossref]

Jones, R. J.

Jost, J. D.

V. Brasch, E. Lucas, J. D. Jost, M. Geiselmann, and T. J. Kippenberg, “Self-referenced photonic chip soliton Kerr frequency comb,” Light: Sci. Appl. 6, e16202 (2017).
[Crossref]

J. D. Jost, T. Herr, C. Lecaplain, V. Brasch, M. H. P. Pfeiffer, and T. J. Kippenberg, “Counting the cycles of light using a self-referenced optical microresonator,” Optica 2, 706–711 (2015).
[Crossref]

T. Herr, V. Brasch, J. D. Jost, C. Y. Wang, N. M. Kondratiev, M. L. Gorodetsky, and T. J. Kippenberg, “Temporal solitons in optical microresonators,” Nat. Photonics 8, 145–152 (2013).
[Crossref]

Kang, S.

Karpov, M.

J. Liu, A. S. Raja, M. Karpov, B. Ghadiani, M. H. P. Pfeiffer, N. J. Engelsen, H. Guo, M. Zervas, and T. J. Kippenberg, “Ultralow-power chip-based soliton microcombs for photonic integration,” Optica 5, 3–9 (2018).
[Crossref]

M. H. P. Pfeiffer, C. Herkommer, J. Liu, H. Guo, M. Karpov, E. Lucas, M. Zervas, and T. J. Kippenberg, “Octave-spanning dissipative Kerr soliton frequency combs in Si3N4 microresonators,” Optica 4, 684–690 (2017).
[Crossref]

Keetman, A.

Kim, S.

King, S. A.

R. M. Godun, P. B. R. Nisbet-Jones, J. M. Jones, S. A. King, L. A. M. Johnson, H. S. Margolis, K. Szymaniec, S. N. Lea, K. Bongs, and P. Gill, “Frequency ratio of two optical clock transitions in 171Yb+ and constraints on the time variation of fundamental constants,” Phys. Rev. Lett. 113, 210801 (2014).
[Crossref]

Kippenberg, T. J.

T. J. Kippenberg, A. L. Gaeta, M. Lipson, and M. L. Gorodetsky, “Dissipative Kerr solitons in optical microresonators,” Science 361, eaan8083 (2018).
[Crossref]

J. Liu, A. S. Raja, M. Karpov, B. Ghadiani, M. H. P. Pfeiffer, N. J. Engelsen, H. Guo, M. Zervas, and T. J. Kippenberg, “Ultralow-power chip-based soliton microcombs for photonic integration,” Optica 5, 3–9 (2018).
[Crossref]

D. T. Spencer, T. Drake, T. C. Briles, J. Stone, L. C. Sinclair, C. Fredrick, Q. Li, D. Westly, B. R. Ilic, A. Bluestone, N. Volet, T. Komljenovic, L. Chang, S. H. Lee, D. Y. Oh, M.-G. Suh, K. Y. Yang, M. H. P. Pfeiffer, T. J. Kippenberg, E. Norberg, L. Theogarajan, K. Vahala, N. R. Newbury, K. Srinivasan, J. E. Bowers, S. A. Diddams, and S. B. Papp, “An optical-frequency synthesizer using integrated photonics,” Nature 557, 81–85 (2018).
[Crossref]

V. Brasch, E. Lucas, J. D. Jost, M. Geiselmann, and T. J. Kippenberg, “Self-referenced photonic chip soliton Kerr frequency comb,” Light: Sci. Appl. 6, e16202 (2017).
[Crossref]

M. H. P. Pfeiffer, C. Herkommer, J. Liu, H. Guo, M. Karpov, E. Lucas, M. Zervas, and T. J. Kippenberg, “Octave-spanning dissipative Kerr soliton frequency combs in Si3N4 microresonators,” Optica 4, 684–690 (2017).
[Crossref]

J. D. Jost, T. Herr, C. Lecaplain, V. Brasch, M. H. P. Pfeiffer, and T. J. Kippenberg, “Counting the cycles of light using a self-referenced optical microresonator,” Optica 2, 706–711 (2015).
[Crossref]

T. Herr, V. Brasch, J. D. Jost, C. Y. Wang, N. M. Kondratiev, M. L. Gorodetsky, and T. J. Kippenberg, “Temporal solitons in optical microresonators,” Nat. Photonics 8, 145–152 (2013).
[Crossref]

Kitching, J.

Kitching, J. E.

Knappe, S.

S. Knappe, V. Shah, P. D. D. Schwindt, L. Hollberg, J. Kitching, L. A. Liew, and J. Moreland, “A microfabricated atomic clock,” Appl. Phys. Lett. 85, 1460–1462 (2004).
[Crossref]

Koller, S.

J. Grotti, S. Koller, S. Vogt, S. Häfner, U. Sterr, C. Lisdat, H. Denker, C. Voigt, L. Timmen, A. Rolland, F. N. Baynes, H. S. Margolis, M. Zampaolo, P. Thoumany, M. Pizzocaro, B. Rauf, F. Bregolin, A. Tampellini, P. Barbieri, M. Zucco, G. A. Costanzo, C. Clivati, F. Levi, and D. Calonico, “Geodesy and metrology with a transportable optical clock,” Nat. Phys. 14, 437–441 (2018).
[Crossref]

Koller, S. B.

S. B. Koller, J. Grotti, S. Vogt, A. Al-Masoudi, S. Dörscher, S. Häfner, U. Sterr, and C. Lisdat, “Transportable optical lattice clock with 7×10-17 uncertainty,” Phys. Rev. Lett. 118, 073601 (2017).
[Crossref]

Komljenovic, T.

D. T. Spencer, T. Drake, T. C. Briles, J. Stone, L. C. Sinclair, C. Fredrick, Q. Li, D. Westly, B. R. Ilic, A. Bluestone, N. Volet, T. Komljenovic, L. Chang, S. H. Lee, D. Y. Oh, M.-G. Suh, K. Y. Yang, M. H. P. Pfeiffer, T. J. Kippenberg, E. Norberg, L. Theogarajan, K. Vahala, N. R. Newbury, K. Srinivasan, J. E. Bowers, S. A. Diddams, and S. B. Papp, “An optical-frequency synthesizer using integrated photonics,” Nature 557, 81–85 (2018).
[Crossref]

Kondratiev, N. M.

T. Herr, V. Brasch, J. D. Jost, C. Y. Wang, N. M. Kondratiev, M. L. Gorodetsky, and T. J. Kippenberg, “Temporal solitons in optical microresonators,” Nat. Photonics 8, 145–152 (2013).
[Crossref]

Kovalchuk, E. V.

Latrasse, C.

J. E. Bernard, A. A. Madej, K. J. Siemsen, L. Marmet, C. Latrasse, D. Touahri, M. Poulin, M. Allard, and M. Tetu, “Absolute frequency measurement of a laser at 1556  nm locked to the 5S1/2-5D5/2 two-photon transition in 87-Rb,” Opt. Commun. 173, 357–364 (2000).
[Crossref]

Lea, S. N.

R. M. Godun, P. B. R. Nisbet-Jones, J. M. Jones, S. A. King, L. A. M. Johnson, H. S. Margolis, K. Szymaniec, S. N. Lea, K. Bongs, and P. Gill, “Frequency ratio of two optical clock transitions in 171Yb+ and constraints on the time variation of fundamental constants,” Phys. Rev. Lett. 113, 210801 (2014).
[Crossref]

Lecaplain, C.

Lee, H.

P. Del’Haye, A. Coillet, T. Fortier, K. Beha, D. C. Cole, K. Y. Yang, H. Lee, K. J. Vahala, S. B. Papp, and S. A. Diddams, “Phase-coherent microwave-to-optical link with a self-referenced microcomb,” Nat. Photonics 10, 516–520 (2016).
[Crossref]

S. B. Papp, K. Beha, P. Del’Haye, F. Quinlan, H. Lee, K. J. Vahala, and S. A. Diddams, “Microresonator frequency comb optical clock,” Optica 1, 10–14 (2014).
[Crossref]

Lee, S. H.

D. T. Spencer, T. Drake, T. C. Briles, J. Stone, L. C. Sinclair, C. Fredrick, Q. Li, D. Westly, B. R. Ilic, A. Bluestone, N. Volet, T. Komljenovic, L. Chang, S. H. Lee, D. Y. Oh, M.-G. Suh, K. Y. Yang, M. H. P. Pfeiffer, T. J. Kippenberg, E. Norberg, L. Theogarajan, K. Vahala, N. R. Newbury, K. Srinivasan, J. E. Bowers, S. A. Diddams, and S. B. Papp, “An optical-frequency synthesizer using integrated photonics,” Nature 557, 81–85 (2018).
[Crossref]

Lee, W. D.

S. A. Diddams, T. Udem, J. C. Bergquist, E. A. Curtis, R. E. Drullinger, L. Hollberg, W. M. Itano, W. D. Lee, C. W. Oates, K. R. Vogel, and D. J. Wineland, “An optical clock based on a single trapped 199Hg+ ion,” Science 293, 825–828 (2001).
[Crossref]

Lemke, N. D.

K. W. Martin, G. Phelps, N. D. Lemke, M. S. Bigelow, B. Stuhl, M. Wojcik, M. Holt, I. Coddington, M. W. Bishop, and J. H. Burke, “Compact optical atomic clock based on a two-photon transition in rubidium,” Phys. Rev. Appl. 9, 014019 (2018).
[Crossref]

Levi, F.

J. Grotti, S. Koller, S. Vogt, S. Häfner, U. Sterr, C. Lisdat, H. Denker, C. Voigt, L. Timmen, A. Rolland, F. N. Baynes, H. S. Margolis, M. Zampaolo, P. Thoumany, M. Pizzocaro, B. Rauf, F. Bregolin, A. Tampellini, P. Barbieri, M. Zucco, G. A. Costanzo, C. Clivati, F. Levi, and D. Calonico, “Geodesy and metrology with a transportable optical clock,” Nat. Phys. 14, 437–441 (2018).
[Crossref]

C. Clivati, G. A. Costanzo, M. Frittelli, F. Levi, A. Mura, M. Zucco, R. Ambrosini, C. Bortolotti, F. Perini, M. Roma, and D. Calonico, “A coherent fiber link for very long baseline interferometry,” IEEE Trans. Ultrason. Ferroelectr. Freq. Control 62, 1907–1912 (2015).
[Crossref]

Li, Q.

M. T. Hummon, S. Kang, D. G. Bopp, Q. Li, D. A. Westly, S. Kim, C. Fredrick, S. A. Diddams, K. Srinivasan, V. Aksyuk, and J. E. Kitching, “Photonic chip for laser stabilization to an atomic vapor with 10-11 instability,” Optica 5, 443–449 (2018).
[Crossref]

T. C. Briles, J. R. Stone, T. E. Drake, D. T. Spencer, C. Frederick, Q. Li, D. A. Westly, B. R. Illic, K. Srinivasan, S. A. Diddams, and S. B. Papp, “Interlocking Kerr-microresonator frequency combs for microwave to optical synthesis,” Opt. Lett. 43, 2933–2936 (2018).
[Crossref]

D. T. Spencer, T. Drake, T. C. Briles, J. Stone, L. C. Sinclair, C. Fredrick, Q. Li, D. Westly, B. R. Ilic, A. Bluestone, N. Volet, T. Komljenovic, L. Chang, S. H. Lee, D. Y. Oh, M.-G. Suh, K. Y. Yang, M. H. P. Pfeiffer, T. J. Kippenberg, E. Norberg, L. Theogarajan, K. Vahala, N. R. Newbury, K. Srinivasan, J. E. Bowers, S. A. Diddams, and S. B. Papp, “An optical-frequency synthesizer using integrated photonics,” Nature 557, 81–85 (2018).
[Crossref]

Q. Li, T. C. Briles, D. A. Westly, T. E. Drake, J. R. Stone, B. R. Ilic, S. A. Diddams, S. B. Papp, and K. Srinivasan, “Stably accessing octave-spanning microresonator frequency combs in the soliton regime,” Optica 4, 193–203 (2016).
[Crossref]

T. E. Drake, T. C. Briles, D. T. Spencer, J. R. Stone, D. R. Carlson, D. D. Hickstein, Q. Li, D. Westly, K. Srinivasan, S. A. Diddams, and S. B. Papp, “A Kerr-microresonator optical clockwork,” arXiv:1811.00581 (2018).

Li, X.

X. Yi, Q.-F. Yang, X. Zhang, K. Y. Yang, X. Li, and K. Vahala, “Single-mode dispersive waves and soliton microcomb dynamics,” Nat. Commun. 8, 14869 (2017).
[Crossref]

Liang, W.

W. Liang, D. Eliyahu, V. S. Ilchenko, A. A. Savchenkov, D. Seidel, L. Maleki, and A. B. Matsko, “High spectral purity Kerr frequency comb radio frequency photonic oscillator,” Nat. Commun. 6, 1–8 (2015).
[Crossref]

A. A. Savchenkov, D. Eliyahu, W. Liang, V. S. Ilchenko, J. Byrd, A. B. Matsko, D. Seidel, and L. Maleki, “Stabilization of a Kerr frequency comb oscillator,” Opt. Lett. 38, 2636–2639 (2013).
[Crossref]

Liew, L. A.

S. Knappe, V. Shah, P. D. D. Schwindt, L. Hollberg, J. Kitching, L. A. Liew, and J. Moreland, “A microfabricated atomic clock,” Appl. Phys. Lett. 85, 1460–1462 (2004).
[Crossref]

Lipson, M.

B. Stern, X. Ji, Y. Okawachi, A. L. Gaeta, and M. Lipson, “Battery-operated integrated frequency comb generator,” Nature 562, 401–405 (2018).
[Crossref]

T. J. Kippenberg, A. L. Gaeta, M. Lipson, and M. L. Gorodetsky, “Dissipative Kerr solitons in optical microresonators,” Science 361, eaan8083 (2018).
[Crossref]

Lisdat, C.

J. Grotti, S. Koller, S. Vogt, S. Häfner, U. Sterr, C. Lisdat, H. Denker, C. Voigt, L. Timmen, A. Rolland, F. N. Baynes, H. S. Margolis, M. Zampaolo, P. Thoumany, M. Pizzocaro, B. Rauf, F. Bregolin, A. Tampellini, P. Barbieri, M. Zucco, G. A. Costanzo, C. Clivati, F. Levi, and D. Calonico, “Geodesy and metrology with a transportable optical clock,” Nat. Phys. 14, 437–441 (2018).
[Crossref]

S. B. Koller, J. Grotti, S. Vogt, A. Al-Masoudi, S. Dörscher, S. Häfner, U. Sterr, and C. Lisdat, “Transportable optical lattice clock with 7×10-17 uncertainty,” Phys. Rev. Lett. 118, 073601 (2017).
[Crossref]

Liu, J.

J. Liu, A. S. Raja, M. Karpov, B. Ghadiani, M. H. P. Pfeiffer, N. J. Engelsen, H. Guo, M. Zervas, and T. J. Kippenberg, “Ultralow-power chip-based soliton microcombs for photonic integration,” Optica 5, 3–9 (2018).
[Crossref]

M. H. P. Pfeiffer, C. Herkommer, J. Liu, H. Guo, M. Karpov, E. Lucas, M. Zervas, and T. J. Kippenberg, “Octave-spanning dissipative Kerr soliton frequency combs in Si3N4 microresonators,” Optica 4, 684–690 (2017).
[Crossref]

Liu, Y.

Lorini, L.

T. Rosenband, D. B. Hume, P. O. Schmidt, C. W. Chou, A. Brusch, L. Lorini, W. H. Oskay, R. E. Drullinger, T. M. Fortier, J. E. Stalnaker, S. A. Diddams, W. C. Swann, N. R. Newbury, W. M. Itano, D. J. Wineland, and J. C. Bergquist, “Frequency ratio of Al+ and Hg+ single-ion optical clocks; metrology at the 17th decimal place,” Science 319, 1808–1812 (2008).
[Crossref]

Lucas, E.

M. H. P. Pfeiffer, C. Herkommer, J. Liu, H. Guo, M. Karpov, E. Lucas, M. Zervas, and T. J. Kippenberg, “Octave-spanning dissipative Kerr soliton frequency combs in Si3N4 microresonators,” Optica 4, 684–690 (2017).
[Crossref]

V. Brasch, E. Lucas, J. D. Jost, M. Geiselmann, and T. J. Kippenberg, “Self-referenced photonic chip soliton Kerr frequency comb,” Light: Sci. Appl. 6, e16202 (2017).
[Crossref]

Ludlow, A. D.

M. Schioppo, R. C. Brown, W. F. McGrew, N. Hinkley, R. J. Fasano, K. Beloy, T. H. Yoon, G. Milani, D. Nicolodi, J. A. Sherman, N. B. Phillips, C. W. Oates, and A. D. Ludlow, “Ultrastable optical clock with two cold-atom ensembles,” Nat. Photonics 11, 48–52 (2016).
[Crossref]

Ma, L.-S.

Madej, A. A.

J. E. Bernard, A. A. Madej, K. J. Siemsen, L. Marmet, C. Latrasse, D. Touahri, M. Poulin, M. Allard, and M. Tetu, “Absolute frequency measurement of a laser at 1556  nm locked to the 5S1/2-5D5/2 two-photon transition in 87-Rb,” Opt. Commun. 173, 357–364 (2000).
[Crossref]

Maleki, L.

W. Liang, D. Eliyahu, V. S. Ilchenko, A. A. Savchenkov, D. Seidel, L. Maleki, and A. B. Matsko, “High spectral purity Kerr frequency comb radio frequency photonic oscillator,” Nat. Commun. 6, 1–8 (2015).
[Crossref]

A. A. Savchenkov, D. Eliyahu, W. Liang, V. S. Ilchenko, J. Byrd, A. B. Matsko, D. Seidel, and L. Maleki, “Stabilization of a Kerr frequency comb oscillator,” Opt. Lett. 38, 2636–2639 (2013).
[Crossref]

Margolis, H. S.

J. Grotti, S. Koller, S. Vogt, S. Häfner, U. Sterr, C. Lisdat, H. Denker, C. Voigt, L. Timmen, A. Rolland, F. N. Baynes, H. S. Margolis, M. Zampaolo, P. Thoumany, M. Pizzocaro, B. Rauf, F. Bregolin, A. Tampellini, P. Barbieri, M. Zucco, G. A. Costanzo, C. Clivati, F. Levi, and D. Calonico, “Geodesy and metrology with a transportable optical clock,” Nat. Phys. 14, 437–441 (2018).
[Crossref]

R. M. Godun, P. B. R. Nisbet-Jones, J. M. Jones, S. A. King, L. A. M. Johnson, H. S. Margolis, K. Szymaniec, S. N. Lea, K. Bongs, and P. Gill, “Frequency ratio of two optical clock transitions in 171Yb+ and constraints on the time variation of fundamental constants,” Phys. Rev. Lett. 113, 210801 (2014).
[Crossref]

Marmet, L.

J. E. Bernard, A. A. Madej, K. J. Siemsen, L. Marmet, C. Latrasse, D. Touahri, M. Poulin, M. Allard, and M. Tetu, “Absolute frequency measurement of a laser at 1556  nm locked to the 5S1/2-5D5/2 two-photon transition in 87-Rb,” Opt. Commun. 173, 357–364 (2000).
[Crossref]

Martin, K. W.

K. W. Martin, G. Phelps, N. D. Lemke, M. S. Bigelow, B. Stuhl, M. Wojcik, M. Holt, I. Coddington, M. W. Bishop, and J. H. Burke, “Compact optical atomic clock based on a two-photon transition in rubidium,” Phys. Rev. Appl. 9, 014019 (2018).
[Crossref]

Matsko, A. B.

W. Liang, D. Eliyahu, V. S. Ilchenko, A. A. Savchenkov, D. Seidel, L. Maleki, and A. B. Matsko, “High spectral purity Kerr frequency comb radio frequency photonic oscillator,” Nat. Commun. 6, 1–8 (2015).
[Crossref]

A. A. Savchenkov, D. Eliyahu, W. Liang, V. S. Ilchenko, J. Byrd, A. B. Matsko, D. Seidel, and L. Maleki, “Stabilization of a Kerr frequency comb oscillator,” Opt. Lett. 38, 2636–2639 (2013).
[Crossref]

McGrew, W. F.

M. Schioppo, R. C. Brown, W. F. McGrew, N. Hinkley, R. J. Fasano, K. Beloy, T. H. Yoon, G. Milani, D. Nicolodi, J. A. Sherman, N. B. Phillips, C. W. Oates, and A. D. Ludlow, “Ultrastable optical clock with two cold-atom ensembles,” Nat. Photonics 11, 48–52 (2016).
[Crossref]

Milani, G.

M. Schioppo, R. C. Brown, W. F. McGrew, N. Hinkley, R. J. Fasano, K. Beloy, T. H. Yoon, G. Milani, D. Nicolodi, J. A. Sherman, N. B. Phillips, C. W. Oates, and A. D. Ludlow, “Ultrastable optical clock with two cold-atom ensembles,” Nat. Photonics 11, 48–52 (2016).
[Crossref]

Moreland, J.

S. Knappe, V. Shah, P. D. D. Schwindt, L. Hollberg, J. Kitching, L. A. Liew, and J. Moreland, “A microfabricated atomic clock,” Appl. Phys. Lett. 85, 1460–1462 (2004).
[Crossref]

Morton, M. J.

Morton, P. A.

Mura, A.

C. Clivati, G. A. Costanzo, M. Frittelli, F. Levi, A. Mura, M. Zucco, R. Ambrosini, C. Bortolotti, F. Perini, M. Roma, and D. Calonico, “A coherent fiber link for very long baseline interferometry,” IEEE Trans. Ultrason. Ferroelectr. Freq. Control 62, 1907–1912 (2015).
[Crossref]

Nelson, K. D.

S. Gundavarapu, G. M. Brodnik, M. Puckett, T. Huffman, D. Bose, R. Behunin, J. Wu, T. Qiu, C. Pinho, N. Chauhan, J. Nohava, P. T. Rakich, K. D. Nelson, M. Salit, and D. J. Blumenthal, “Sub-hertz fundamental linewidth photonic integrated Brillouin laser,” Nat. Photonics 13, 60–67 (2018).
[Crossref]

Newbury, N. R.

D. T. Spencer, T. Drake, T. C. Briles, J. Stone, L. C. Sinclair, C. Fredrick, Q. Li, D. Westly, B. R. Ilic, A. Bluestone, N. Volet, T. Komljenovic, L. Chang, S. H. Lee, D. Y. Oh, M.-G. Suh, K. Y. Yang, M. H. P. Pfeiffer, T. J. Kippenberg, E. Norberg, L. Theogarajan, K. Vahala, N. R. Newbury, K. Srinivasan, J. E. Bowers, S. A. Diddams, and S. B. Papp, “An optical-frequency synthesizer using integrated photonics,” Nature 557, 81–85 (2018).
[Crossref]

T. Rosenband, D. B. Hume, P. O. Schmidt, C. W. Chou, A. Brusch, L. Lorini, W. H. Oskay, R. E. Drullinger, T. M. Fortier, J. E. Stalnaker, S. A. Diddams, W. C. Swann, N. R. Newbury, W. M. Itano, D. J. Wineland, and J. C. Bergquist, “Frequency ratio of Al+ and Hg+ single-ion optical clocks; metrology at the 17th decimal place,” Science 319, 1808–1812 (2008).
[Crossref]

Nicolodi, D.

M. Schioppo, R. C. Brown, W. F. McGrew, N. Hinkley, R. J. Fasano, K. Beloy, T. H. Yoon, G. Milani, D. Nicolodi, J. A. Sherman, N. B. Phillips, C. W. Oates, and A. D. Ludlow, “Ultrastable optical clock with two cold-atom ensembles,” Nat. Photonics 11, 48–52 (2016).
[Crossref]

Nisbet-Jones, P. B. R.

R. M. Godun, P. B. R. Nisbet-Jones, J. M. Jones, S. A. King, L. A. M. Johnson, H. S. Margolis, K. Szymaniec, S. N. Lea, K. Bongs, and P. Gill, “Frequency ratio of two optical clock transitions in 171Yb+ and constraints on the time variation of fundamental constants,” Phys. Rev. Lett. 113, 210801 (2014).
[Crossref]

Nohava, J.

S. Gundavarapu, G. M. Brodnik, M. Puckett, T. Huffman, D. Bose, R. Behunin, J. Wu, T. Qiu, C. Pinho, N. Chauhan, J. Nohava, P. T. Rakich, K. D. Nelson, M. Salit, and D. J. Blumenthal, “Sub-hertz fundamental linewidth photonic integrated Brillouin laser,” Nat. Photonics 13, 60–67 (2018).
[Crossref]

Norberg, E.

D. T. Spencer, T. Drake, T. C. Briles, J. Stone, L. C. Sinclair, C. Fredrick, Q. Li, D. Westly, B. R. Ilic, A. Bluestone, N. Volet, T. Komljenovic, L. Chang, S. H. Lee, D. Y. Oh, M.-G. Suh, K. Y. Yang, M. H. P. Pfeiffer, T. J. Kippenberg, E. Norberg, L. Theogarajan, K. Vahala, N. R. Newbury, K. Srinivasan, J. E. Bowers, S. A. Diddams, and S. B. Papp, “An optical-frequency synthesizer using integrated photonics,” Nature 557, 81–85 (2018).
[Crossref]

Novack, A.

Oates, C. W.

M. Schioppo, R. C. Brown, W. F. McGrew, N. Hinkley, R. J. Fasano, K. Beloy, T. H. Yoon, G. Milani, D. Nicolodi, J. A. Sherman, N. B. Phillips, C. W. Oates, and A. D. Ludlow, “Ultrastable optical clock with two cold-atom ensembles,” Nat. Photonics 11, 48–52 (2016).
[Crossref]

S. A. Diddams, T. Udem, J. C. Bergquist, E. A. Curtis, R. E. Drullinger, L. Hollberg, W. M. Itano, W. D. Lee, C. W. Oates, K. R. Vogel, and D. J. Wineland, “An optical clock based on a single trapped 199Hg+ ion,” Science 293, 825–828 (2001).
[Crossref]

Oh, D. Y.

D. T. Spencer, T. Drake, T. C. Briles, J. Stone, L. C. Sinclair, C. Fredrick, Q. Li, D. Westly, B. R. Ilic, A. Bluestone, N. Volet, T. Komljenovic, L. Chang, S. H. Lee, D. Y. Oh, M.-G. Suh, K. Y. Yang, M. H. P. Pfeiffer, T. J. Kippenberg, E. Norberg, L. Theogarajan, K. Vahala, N. R. Newbury, K. Srinivasan, J. E. Bowers, S. A. Diddams, and S. B. Papp, “An optical-frequency synthesizer using integrated photonics,” Nature 557, 81–85 (2018).
[Crossref]

Okawachi, Y.

B. Stern, X. Ji, Y. Okawachi, A. L. Gaeta, and M. Lipson, “Battery-operated integrated frequency comb generator,” Nature 562, 401–405 (2018).
[Crossref]

Oskay, W. H.

T. Rosenband, D. B. Hume, P. O. Schmidt, C. W. Chou, A. Brusch, L. Lorini, W. H. Oskay, R. E. Drullinger, T. M. Fortier, J. E. Stalnaker, S. A. Diddams, W. C. Swann, N. R. Newbury, W. M. Itano, D. J. Wineland, and J. C. Bergquist, “Frequency ratio of Al+ and Hg+ single-ion optical clocks; metrology at the 17th decimal place,” Science 319, 1808–1812 (2008).
[Crossref]

Pahl, J.

Papp, S. B.

D. T. Spencer, T. Drake, T. C. Briles, J. Stone, L. C. Sinclair, C. Fredrick, Q. Li, D. Westly, B. R. Ilic, A. Bluestone, N. Volet, T. Komljenovic, L. Chang, S. H. Lee, D. Y. Oh, M.-G. Suh, K. Y. Yang, M. H. P. Pfeiffer, T. J. Kippenberg, E. Norberg, L. Theogarajan, K. Vahala, N. R. Newbury, K. Srinivasan, J. E. Bowers, S. A. Diddams, and S. B. Papp, “An optical-frequency synthesizer using integrated photonics,” Nature 557, 81–85 (2018).
[Crossref]

T. C. Briles, J. R. Stone, T. E. Drake, D. T. Spencer, C. Frederick, Q. Li, D. A. Westly, B. R. Illic, K. Srinivasan, S. A. Diddams, and S. B. Papp, “Interlocking Kerr-microresonator frequency combs for microwave to optical synthesis,” Opt. Lett. 43, 2933–2936 (2018).
[Crossref]

J. R. Stone, T. C. Briles, T. E. Drake, D. T. Spencer, D. R. Carlson, S. A. Diddams, and S. B. Papp, “Thermal and nonlinear dissipative-soliton dynamics in Kerr-microresonator frequency combs,” Phys. Rev. Lett. 121, 63902 (2018).
[Crossref]

P. Del’Haye, A. Coillet, T. Fortier, K. Beha, D. C. Cole, K. Y. Yang, H. Lee, K. J. Vahala, S. B. Papp, and S. A. Diddams, “Phase-coherent microwave-to-optical link with a self-referenced microcomb,” Nat. Photonics 10, 516–520 (2016).
[Crossref]

Q. Li, T. C. Briles, D. A. Westly, T. E. Drake, J. R. Stone, B. R. Ilic, S. A. Diddams, S. B. Papp, and K. Srinivasan, “Stably accessing octave-spanning microresonator frequency combs in the soliton regime,” Optica 4, 193–203 (2016).
[Crossref]

S. B. Papp, K. Beha, P. Del’Haye, F. Quinlan, H. Lee, K. J. Vahala, and S. A. Diddams, “Microresonator frequency comb optical clock,” Optica 1, 10–14 (2014).
[Crossref]

T. E. Drake, T. C. Briles, D. T. Spencer, J. R. Stone, D. R. Carlson, D. D. Hickstein, Q. Li, D. Westly, K. Srinivasan, S. A. Diddams, and S. B. Papp, “A Kerr-microresonator optical clockwork,” arXiv:1811.00581 (2018).

Peng, J.-L.

Perini, F.

C. Clivati, G. A. Costanzo, M. Frittelli, F. Levi, A. Mura, M. Zucco, R. Ambrosini, C. Bortolotti, F. Perini, M. Roma, and D. Calonico, “A coherent fiber link for very long baseline interferometry,” IEEE Trans. Ultrason. Ferroelectr. Freq. Control 62, 1907–1912 (2015).
[Crossref]

Peters, A.

Pfeiffer, M. H. P.

J. Liu, A. S. Raja, M. Karpov, B. Ghadiani, M. H. P. Pfeiffer, N. J. Engelsen, H. Guo, M. Zervas, and T. J. Kippenberg, “Ultralow-power chip-based soliton microcombs for photonic integration,” Optica 5, 3–9 (2018).
[Crossref]

D. T. Spencer, T. Drake, T. C. Briles, J. Stone, L. C. Sinclair, C. Fredrick, Q. Li, D. Westly, B. R. Ilic, A. Bluestone, N. Volet, T. Komljenovic, L. Chang, S. H. Lee, D. Y. Oh, M.-G. Suh, K. Y. Yang, M. H. P. Pfeiffer, T. J. Kippenberg, E. Norberg, L. Theogarajan, K. Vahala, N. R. Newbury, K. Srinivasan, J. E. Bowers, S. A. Diddams, and S. B. Papp, “An optical-frequency synthesizer using integrated photonics,” Nature 557, 81–85 (2018).
[Crossref]

M. H. P. Pfeiffer, C. Herkommer, J. Liu, H. Guo, M. Karpov, E. Lucas, M. Zervas, and T. J. Kippenberg, “Octave-spanning dissipative Kerr soliton frequency combs in Si3N4 microresonators,” Optica 4, 684–690 (2017).
[Crossref]

J. D. Jost, T. Herr, C. Lecaplain, V. Brasch, M. H. P. Pfeiffer, and T. J. Kippenberg, “Counting the cycles of light using a self-referenced optical microresonator,” Optica 2, 706–711 (2015).
[Crossref]

Phelps, G.

K. W. Martin, G. Phelps, N. D. Lemke, M. S. Bigelow, B. Stuhl, M. Wojcik, M. Holt, I. Coddington, M. W. Bishop, and J. H. Burke, “Compact optical atomic clock based on a two-photon transition in rubidium,” Phys. Rev. Appl. 9, 014019 (2018).
[Crossref]

Phillips, N. B.

M. Schioppo, R. C. Brown, W. F. McGrew, N. Hinkley, R. J. Fasano, K. Beloy, T. H. Yoon, G. Milani, D. Nicolodi, J. A. Sherman, N. B. Phillips, C. W. Oates, and A. D. Ludlow, “Ultrastable optical clock with two cold-atom ensembles,” Nat. Photonics 11, 48–52 (2016).
[Crossref]

Pinho, C.

S. Gundavarapu, G. M. Brodnik, M. Puckett, T. Huffman, D. Bose, R. Behunin, J. Wu, T. Qiu, C. Pinho, N. Chauhan, J. Nohava, P. T. Rakich, K. D. Nelson, M. Salit, and D. J. Blumenthal, “Sub-hertz fundamental linewidth photonic integrated Brillouin laser,” Nat. Photonics 13, 60–67 (2018).
[Crossref]

Pizzocaro, M.

J. Grotti, S. Koller, S. Vogt, S. Häfner, U. Sterr, C. Lisdat, H. Denker, C. Voigt, L. Timmen, A. Rolland, F. N. Baynes, H. S. Margolis, M. Zampaolo, P. Thoumany, M. Pizzocaro, B. Rauf, F. Bregolin, A. Tampellini, P. Barbieri, M. Zucco, G. A. Costanzo, C. Clivati, F. Levi, and D. Calonico, “Geodesy and metrology with a transportable optical clock,” Nat. Phys. 14, 437–441 (2018).
[Crossref]

Poulin, M.

J. E. Bernard, A. A. Madej, K. J. Siemsen, L. Marmet, C. Latrasse, D. Touahri, M. Poulin, M. Allard, and M. Tetu, “Absolute frequency measurement of a laser at 1556  nm locked to the 5S1/2-5D5/2 two-photon transition in 87-Rb,” Opt. Commun. 173, 357–364 (2000).
[Crossref]

Puckett, M.

S. Gundavarapu, G. M. Brodnik, M. Puckett, T. Huffman, D. Bose, R. Behunin, J. Wu, T. Qiu, C. Pinho, N. Chauhan, J. Nohava, P. T. Rakich, K. D. Nelson, M. Salit, and D. J. Blumenthal, “Sub-hertz fundamental linewidth photonic integrated Brillouin laser,” Nat. Photonics 13, 60–67 (2018).
[Crossref]

Qiu, T.

S. Gundavarapu, G. M. Brodnik, M. Puckett, T. Huffman, D. Bose, R. Behunin, J. Wu, T. Qiu, C. Pinho, N. Chauhan, J. Nohava, P. T. Rakich, K. D. Nelson, M. Salit, and D. J. Blumenthal, “Sub-hertz fundamental linewidth photonic integrated Brillouin laser,” Nat. Photonics 13, 60–67 (2018).
[Crossref]

Quinlan, F.

Raja, A. S.

J. Liu, A. S. Raja, M. Karpov, B. Ghadiani, M. H. P. Pfeiffer, N. J. Engelsen, H. Guo, M. Zervas, and T. J. Kippenberg, “Ultralow-power chip-based soliton microcombs for photonic integration,” Optica 5, 3–9 (2018).
[Crossref]

Rakich, P. T.

S. Gundavarapu, G. M. Brodnik, M. Puckett, T. Huffman, D. Bose, R. Behunin, J. Wu, T. Qiu, C. Pinho, N. Chauhan, J. Nohava, P. T. Rakich, K. D. Nelson, M. Salit, and D. J. Blumenthal, “Sub-hertz fundamental linewidth photonic integrated Brillouin laser,” Nat. Photonics 13, 60–67 (2018).
[Crossref]

Randle, H. G.

Ranka, J. K.

D. J. Jones, S. A. Diddams, J. K. Ranka, A. Stentz, R. S. Windeler, J. L. Hall, and S. T. Cundiff, “Carrier-envelope phase control of femtosecond mode-locked lasers and direct optical frequency synthesis,” Science 288, 635–639 (2000).
[Crossref]

Rauf, B.

J. Grotti, S. Koller, S. Vogt, S. Häfner, U. Sterr, C. Lisdat, H. Denker, C. Voigt, L. Timmen, A. Rolland, F. N. Baynes, H. S. Margolis, M. Zampaolo, P. Thoumany, M. Pizzocaro, B. Rauf, F. Bregolin, A. Tampellini, P. Barbieri, M. Zucco, G. A. Costanzo, C. Clivati, F. Levi, and D. Calonico, “Geodesy and metrology with a transportable optical clock,” Nat. Phys. 14, 437–441 (2018).
[Crossref]

Riehle, F.

F. Riehle, “Optical clock networks,” Nat. Photonics 11, 25–31 (2017).
[Crossref]

F. Riehle, “Towards a redefinition of the second based on optical atomic clocks,” Comptes Rendus Phys. 16, 506–515 (2015).
[Crossref]

Robertsson, L.

Rolland, A.

J. Grotti, S. Koller, S. Vogt, S. Häfner, U. Sterr, C. Lisdat, H. Denker, C. Voigt, L. Timmen, A. Rolland, F. N. Baynes, H. S. Margolis, M. Zampaolo, P. Thoumany, M. Pizzocaro, B. Rauf, F. Bregolin, A. Tampellini, P. Barbieri, M. Zucco, G. A. Costanzo, C. Clivati, F. Levi, and D. Calonico, “Geodesy and metrology with a transportable optical clock,” Nat. Phys. 14, 437–441 (2018).
[Crossref]

Roma, M.

C. Clivati, G. A. Costanzo, M. Frittelli, F. Levi, A. Mura, M. Zucco, R. Ambrosini, C. Bortolotti, F. Perini, M. Roma, and D. Calonico, “A coherent fiber link for very long baseline interferometry,” IEEE Trans. Ultrason. Ferroelectr. Freq. Control 62, 1907–1912 (2015).
[Crossref]

Roman, J.

Rosenband, T.

T. Rosenband, D. B. Hume, P. O. Schmidt, C. W. Chou, A. Brusch, L. Lorini, W. H. Oskay, R. E. Drullinger, T. M. Fortier, J. E. Stalnaker, S. A. Diddams, W. C. Swann, N. R. Newbury, W. M. Itano, D. J. Wineland, and J. C. Bergquist, “Frequency ratio of Al+ and Hg+ single-ion optical clocks; metrology at the 17th decimal place,” Science 319, 1808–1812 (2008).
[Crossref]

Salit, M.

S. Gundavarapu, G. M. Brodnik, M. Puckett, T. Huffman, D. Bose, R. Behunin, J. Wu, T. Qiu, C. Pinho, N. Chauhan, J. Nohava, P. T. Rakich, K. D. Nelson, M. Salit, and D. J. Blumenthal, “Sub-hertz fundamental linewidth photonic integrated Brillouin laser,” Nat. Photonics 13, 60–67 (2018).
[Crossref]

Savchenkov, A. A.

W. Liang, D. Eliyahu, V. S. Ilchenko, A. A. Savchenkov, D. Seidel, L. Maleki, and A. B. Matsko, “High spectral purity Kerr frequency comb radio frequency photonic oscillator,” Nat. Commun. 6, 1–8 (2015).
[Crossref]

A. A. Savchenkov, D. Eliyahu, W. Liang, V. S. Ilchenko, J. Byrd, A. B. Matsko, D. Seidel, and L. Maleki, “Stabilization of a Kerr frequency comb oscillator,” Opt. Lett. 38, 2636–2639 (2013).
[Crossref]

Schioppo, M.

M. Schioppo, R. C. Brown, W. F. McGrew, N. Hinkley, R. J. Fasano, K. Beloy, T. H. Yoon, G. Milani, D. Nicolodi, J. A. Sherman, N. B. Phillips, C. W. Oates, and A. D. Ludlow, “Ultrastable optical clock with two cold-atom ensembles,” Nat. Photonics 11, 48–52 (2016).
[Crossref]

Schmidt, P. O.

T. Rosenband, D. B. Hume, P. O. Schmidt, C. W. Chou, A. Brusch, L. Lorini, W. H. Oskay, R. E. Drullinger, T. M. Fortier, J. E. Stalnaker, S. A. Diddams, W. C. Swann, N. R. Newbury, W. M. Itano, D. J. Wineland, and J. C. Bergquist, “Frequency ratio of Al+ and Hg+ single-ion optical clocks; metrology at the 17th decimal place,” Science 319, 1808–1812 (2008).
[Crossref]

Schuldt, T.

Schwindt, P. D. D.

S. Knappe, V. Shah, P. D. D. Schwindt, L. Hollberg, J. Kitching, L. A. Liew, and J. Moreland, “A microfabricated atomic clock,” Appl. Phys. Lett. 85, 1460–1462 (2004).
[Crossref]

Seidel, D.

W. Liang, D. Eliyahu, V. S. Ilchenko, A. A. Savchenkov, D. Seidel, L. Maleki, and A. B. Matsko, “High spectral purity Kerr frequency comb radio frequency photonic oscillator,” Nat. Commun. 6, 1–8 (2015).
[Crossref]

A. A. Savchenkov, D. Eliyahu, W. Liang, V. S. Ilchenko, J. Byrd, A. B. Matsko, D. Seidel, and L. Maleki, “Stabilization of a Kerr frequency comb oscillator,” Opt. Lett. 38, 2636–2639 (2013).
[Crossref]

Shah, V.

S. Knappe, V. Shah, P. D. D. Schwindt, L. Hollberg, J. Kitching, L. A. Liew, and J. Moreland, “A microfabricated atomic clock,” Appl. Phys. Lett. 85, 1460–1462 (2004).
[Crossref]

Sherman, J. A.

M. Schioppo, R. C. Brown, W. F. McGrew, N. Hinkley, R. J. Fasano, K. Beloy, T. H. Yoon, G. Milani, D. Nicolodi, J. A. Sherman, N. B. Phillips, C. W. Oates, and A. D. Ludlow, “Ultrastable optical clock with two cold-atom ensembles,” Nat. Photonics 11, 48–52 (2016).
[Crossref]

Shi, R.

Siemsen, K. J.

J. E. Bernard, A. A. Madej, K. J. Siemsen, L. Marmet, C. Latrasse, D. Touahri, M. Poulin, M. Allard, and M. Tetu, “Absolute frequency measurement of a laser at 1556  nm locked to the 5S1/2-5D5/2 two-photon transition in 87-Rb,” Opt. Commun. 173, 357–364 (2000).
[Crossref]

Sinclair, L. C.

D. T. Spencer, T. Drake, T. C. Briles, J. Stone, L. C. Sinclair, C. Fredrick, Q. Li, D. Westly, B. R. Ilic, A. Bluestone, N. Volet, T. Komljenovic, L. Chang, S. H. Lee, D. Y. Oh, M.-G. Suh, K. Y. Yang, M. H. P. Pfeiffer, T. J. Kippenberg, E. Norberg, L. Theogarajan, K. Vahala, N. R. Newbury, K. Srinivasan, J. E. Bowers, S. A. Diddams, and S. B. Papp, “An optical-frequency synthesizer using integrated photonics,” Nature 557, 81–85 (2018).
[Crossref]

Spencer, D. T.

D. T. Spencer, T. Drake, T. C. Briles, J. Stone, L. C. Sinclair, C. Fredrick, Q. Li, D. Westly, B. R. Ilic, A. Bluestone, N. Volet, T. Komljenovic, L. Chang, S. H. Lee, D. Y. Oh, M.-G. Suh, K. Y. Yang, M. H. P. Pfeiffer, T. J. Kippenberg, E. Norberg, L. Theogarajan, K. Vahala, N. R. Newbury, K. Srinivasan, J. E. Bowers, S. A. Diddams, and S. B. Papp, “An optical-frequency synthesizer using integrated photonics,” Nature 557, 81–85 (2018).
[Crossref]

T. C. Briles, J. R. Stone, T. E. Drake, D. T. Spencer, C. Frederick, Q. Li, D. A. Westly, B. R. Illic, K. Srinivasan, S. A. Diddams, and S. B. Papp, “Interlocking Kerr-microresonator frequency combs for microwave to optical synthesis,” Opt. Lett. 43, 2933–2936 (2018).
[Crossref]

J. R. Stone, T. C. Briles, T. E. Drake, D. T. Spencer, D. R. Carlson, S. A. Diddams, and S. B. Papp, “Thermal and nonlinear dissipative-soliton dynamics in Kerr-microresonator frequency combs,” Phys. Rev. Lett. 121, 63902 (2018).
[Crossref]

T. E. Drake, T. C. Briles, D. T. Spencer, J. R. Stone, D. R. Carlson, D. D. Hickstein, Q. Li, D. Westly, K. Srinivasan, S. A. Diddams, and S. B. Papp, “A Kerr-microresonator optical clockwork,” arXiv:1811.00581 (2018).

Srinivasan, K.

T. C. Briles, J. R. Stone, T. E. Drake, D. T. Spencer, C. Frederick, Q. Li, D. A. Westly, B. R. Illic, K. Srinivasan, S. A. Diddams, and S. B. Papp, “Interlocking Kerr-microresonator frequency combs for microwave to optical synthesis,” Opt. Lett. 43, 2933–2936 (2018).
[Crossref]

D. T. Spencer, T. Drake, T. C. Briles, J. Stone, L. C. Sinclair, C. Fredrick, Q. Li, D. Westly, B. R. Ilic, A. Bluestone, N. Volet, T. Komljenovic, L. Chang, S. H. Lee, D. Y. Oh, M.-G. Suh, K. Y. Yang, M. H. P. Pfeiffer, T. J. Kippenberg, E. Norberg, L. Theogarajan, K. Vahala, N. R. Newbury, K. Srinivasan, J. E. Bowers, S. A. Diddams, and S. B. Papp, “An optical-frequency synthesizer using integrated photonics,” Nature 557, 81–85 (2018).
[Crossref]

M. T. Hummon, S. Kang, D. G. Bopp, Q. Li, D. A. Westly, S. Kim, C. Fredrick, S. A. Diddams, K. Srinivasan, V. Aksyuk, and J. E. Kitching, “Photonic chip for laser stabilization to an atomic vapor with 10-11 instability,” Optica 5, 443–449 (2018).
[Crossref]

Q. Li, T. C. Briles, D. A. Westly, T. E. Drake, J. R. Stone, B. R. Ilic, S. A. Diddams, S. B. Papp, and K. Srinivasan, “Stably accessing octave-spanning microresonator frequency combs in the soliton regime,” Optica 4, 193–203 (2016).
[Crossref]

T. E. Drake, T. C. Briles, D. T. Spencer, J. R. Stone, D. R. Carlson, D. D. Hickstein, Q. Li, D. Westly, K. Srinivasan, S. A. Diddams, and S. B. Papp, “A Kerr-microresonator optical clockwork,” arXiv:1811.00581 (2018).

Stalnaker, J. E.

T. Rosenband, D. B. Hume, P. O. Schmidt, C. W. Chou, A. Brusch, L. Lorini, W. H. Oskay, R. E. Drullinger, T. M. Fortier, J. E. Stalnaker, S. A. Diddams, W. C. Swann, N. R. Newbury, W. M. Itano, D. J. Wineland, and J. C. Bergquist, “Frequency ratio of Al+ and Hg+ single-ion optical clocks; metrology at the 17th decimal place,” Science 319, 1808–1812 (2008).
[Crossref]

Stentz, A.

D. J. Jones, S. A. Diddams, J. K. Ranka, A. Stentz, R. S. Windeler, J. L. Hall, and S. T. Cundiff, “Carrier-envelope phase control of femtosecond mode-locked lasers and direct optical frequency synthesis,” Science 288, 635–639 (2000).
[Crossref]

Stern, B.

B. Stern, X. Ji, Y. Okawachi, A. L. Gaeta, and M. Lipson, “Battery-operated integrated frequency comb generator,” Nature 562, 401–405 (2018).
[Crossref]

Sterr, U.

J. Grotti, S. Koller, S. Vogt, S. Häfner, U. Sterr, C. Lisdat, H. Denker, C. Voigt, L. Timmen, A. Rolland, F. N. Baynes, H. S. Margolis, M. Zampaolo, P. Thoumany, M. Pizzocaro, B. Rauf, F. Bregolin, A. Tampellini, P. Barbieri, M. Zucco, G. A. Costanzo, C. Clivati, F. Levi, and D. Calonico, “Geodesy and metrology with a transportable optical clock,” Nat. Phys. 14, 437–441 (2018).
[Crossref]

S. B. Koller, J. Grotti, S. Vogt, A. Al-Masoudi, S. Dörscher, S. Häfner, U. Sterr, and C. Lisdat, “Transportable optical lattice clock with 7×10-17 uncertainty,” Phys. Rev. Lett. 118, 073601 (2017).
[Crossref]

Stone, J.

D. T. Spencer, T. Drake, T. C. Briles, J. Stone, L. C. Sinclair, C. Fredrick, Q. Li, D. Westly, B. R. Ilic, A. Bluestone, N. Volet, T. Komljenovic, L. Chang, S. H. Lee, D. Y. Oh, M.-G. Suh, K. Y. Yang, M. H. P. Pfeiffer, T. J. Kippenberg, E. Norberg, L. Theogarajan, K. Vahala, N. R. Newbury, K. Srinivasan, J. E. Bowers, S. A. Diddams, and S. B. Papp, “An optical-frequency synthesizer using integrated photonics,” Nature 557, 81–85 (2018).
[Crossref]

Stone, J. R.

T. C. Briles, J. R. Stone, T. E. Drake, D. T. Spencer, C. Frederick, Q. Li, D. A. Westly, B. R. Illic, K. Srinivasan, S. A. Diddams, and S. B. Papp, “Interlocking Kerr-microresonator frequency combs for microwave to optical synthesis,” Opt. Lett. 43, 2933–2936 (2018).
[Crossref]

J. R. Stone, T. C. Briles, T. E. Drake, D. T. Spencer, D. R. Carlson, S. A. Diddams, and S. B. Papp, “Thermal and nonlinear dissipative-soliton dynamics in Kerr-microresonator frequency combs,” Phys. Rev. Lett. 121, 63902 (2018).
[Crossref]

Q. Li, T. C. Briles, D. A. Westly, T. E. Drake, J. R. Stone, B. R. Ilic, S. A. Diddams, S. B. Papp, and K. Srinivasan, “Stably accessing octave-spanning microresonator frequency combs in the soliton regime,” Optica 4, 193–203 (2016).
[Crossref]

T. E. Drake, T. C. Briles, D. T. Spencer, J. R. Stone, D. R. Carlson, D. D. Hickstein, Q. Li, D. Westly, K. Srinivasan, S. A. Diddams, and S. B. Papp, “A Kerr-microresonator optical clockwork,” arXiv:1811.00581 (2018).

Stuhl, B.

K. W. Martin, G. Phelps, N. D. Lemke, M. S. Bigelow, B. Stuhl, M. Wojcik, M. Holt, I. Coddington, M. W. Bishop, and J. H. Burke, “Compact optical atomic clock based on a two-photon transition in rubidium,” Phys. Rev. Appl. 9, 014019 (2018).
[Crossref]

Suh, M.-G.

D. T. Spencer, T. Drake, T. C. Briles, J. Stone, L. C. Sinclair, C. Fredrick, Q. Li, D. Westly, B. R. Ilic, A. Bluestone, N. Volet, T. Komljenovic, L. Chang, S. H. Lee, D. Y. Oh, M.-G. Suh, K. Y. Yang, M. H. P. Pfeiffer, T. J. Kippenberg, E. Norberg, L. Theogarajan, K. Vahala, N. R. Newbury, K. Srinivasan, J. E. Bowers, S. A. Diddams, and S. B. Papp, “An optical-frequency synthesizer using integrated photonics,” Nature 557, 81–85 (2018).
[Crossref]

Swann, W. C.

T. Rosenband, D. B. Hume, P. O. Schmidt, C. W. Chou, A. Brusch, L. Lorini, W. H. Oskay, R. E. Drullinger, T. M. Fortier, J. E. Stalnaker, S. A. Diddams, W. C. Swann, N. R. Newbury, W. M. Itano, D. J. Wineland, and J. C. Bergquist, “Frequency ratio of Al+ and Hg+ single-ion optical clocks; metrology at the 17th decimal place,” Science 319, 1808–1812 (2008).
[Crossref]

Sylvestre, T.

Szymaniec, K.

R. M. Godun, P. B. R. Nisbet-Jones, J. M. Jones, S. A. King, L. A. M. Johnson, H. S. Margolis, K. Szymaniec, S. N. Lea, K. Bongs, and P. Gill, “Frequency ratio of two optical clock transitions in 171Yb+ and constraints on the time variation of fundamental constants,” Phys. Rev. Lett. 113, 210801 (2014).
[Crossref]

Tampellini, A.

J. Grotti, S. Koller, S. Vogt, S. Häfner, U. Sterr, C. Lisdat, H. Denker, C. Voigt, L. Timmen, A. Rolland, F. N. Baynes, H. S. Margolis, M. Zampaolo, P. Thoumany, M. Pizzocaro, B. Rauf, F. Bregolin, A. Tampellini, P. Barbieri, M. Zucco, G. A. Costanzo, C. Clivati, F. Levi, and D. Calonico, “Geodesy and metrology with a transportable optical clock,” Nat. Phys. 14, 437–441 (2018).
[Crossref]

Tang, H. X.

Tetu, M.

J. E. Bernard, A. A. Madej, K. J. Siemsen, L. Marmet, C. Latrasse, D. Touahri, M. Poulin, M. Allard, and M. Tetu, “Absolute frequency measurement of a laser at 1556  nm locked to the 5S1/2-5D5/2 two-photon transition in 87-Rb,” Opt. Commun. 173, 357–364 (2000).
[Crossref]

Theogarajan, L.

D. T. Spencer, T. Drake, T. C. Briles, J. Stone, L. C. Sinclair, C. Fredrick, Q. Li, D. Westly, B. R. Ilic, A. Bluestone, N. Volet, T. Komljenovic, L. Chang, S. H. Lee, D. Y. Oh, M.-G. Suh, K. Y. Yang, M. H. P. Pfeiffer, T. J. Kippenberg, E. Norberg, L. Theogarajan, K. Vahala, N. R. Newbury, K. Srinivasan, J. E. Bowers, S. A. Diddams, and S. B. Papp, “An optical-frequency synthesizer using integrated photonics,” Nature 557, 81–85 (2018).
[Crossref]

Thoumany, P.

J. Grotti, S. Koller, S. Vogt, S. Häfner, U. Sterr, C. Lisdat, H. Denker, C. Voigt, L. Timmen, A. Rolland, F. N. Baynes, H. S. Margolis, M. Zampaolo, P. Thoumany, M. Pizzocaro, B. Rauf, F. Bregolin, A. Tampellini, P. Barbieri, M. Zucco, G. A. Costanzo, C. Clivati, F. Levi, and D. Calonico, “Geodesy and metrology with a transportable optical clock,” Nat. Phys. 14, 437–441 (2018).
[Crossref]

Timmen, L.

J. Grotti, S. Koller, S. Vogt, S. Häfner, U. Sterr, C. Lisdat, H. Denker, C. Voigt, L. Timmen, A. Rolland, F. N. Baynes, H. S. Margolis, M. Zampaolo, P. Thoumany, M. Pizzocaro, B. Rauf, F. Bregolin, A. Tampellini, P. Barbieri, M. Zucco, G. A. Costanzo, C. Clivati, F. Levi, and D. Calonico, “Geodesy and metrology with a transportable optical clock,” Nat. Phys. 14, 437–441 (2018).
[Crossref]

Touahri, D.

J. E. Bernard, A. A. Madej, K. J. Siemsen, L. Marmet, C. Latrasse, D. Touahri, M. Poulin, M. Allard, and M. Tetu, “Absolute frequency measurement of a laser at 1556  nm locked to the 5S1/2-5D5/2 two-photon transition in 87-Rb,” Opt. Commun. 173, 357–364 (2000).
[Crossref]

L. Hilico, R. Felder, D. Touahri, O. Acef, A. Clairon, and F. Biraben, “Metrological features of the rubidium two-photon standards of the BNM-LPTF and Kastler Brossel Laboratories,” Eur. Phys. J. Appl. Phys. 4, 219–225 (1998).
[Crossref]

Udem, T.

S. A. Diddams, T. Udem, J. C. Bergquist, E. A. Curtis, R. E. Drullinger, L. Hollberg, W. M. Itano, W. D. Lee, C. W. Oates, K. R. Vogel, and D. J. Wineland, “An optical clock based on a single trapped 199Hg+ ion,” Science 293, 825–828 (2001).
[Crossref]

Vahala, K.

D. T. Spencer, T. Drake, T. C. Briles, J. Stone, L. C. Sinclair, C. Fredrick, Q. Li, D. Westly, B. R. Ilic, A. Bluestone, N. Volet, T. Komljenovic, L. Chang, S. H. Lee, D. Y. Oh, M.-G. Suh, K. Y. Yang, M. H. P. Pfeiffer, T. J. Kippenberg, E. Norberg, L. Theogarajan, K. Vahala, N. R. Newbury, K. Srinivasan, J. E. Bowers, S. A. Diddams, and S. B. Papp, “An optical-frequency synthesizer using integrated photonics,” Nature 557, 81–85 (2018).
[Crossref]

X. Yi, Q.-F. Yang, X. Zhang, K. Y. Yang, X. Li, and K. Vahala, “Single-mode dispersive waves and soliton microcomb dynamics,” Nat. Commun. 8, 14869 (2017).
[Crossref]

Vahala, K. J.

P. Del’Haye, A. Coillet, T. Fortier, K. Beha, D. C. Cole, K. Y. Yang, H. Lee, K. J. Vahala, S. B. Papp, and S. A. Diddams, “Phase-coherent microwave-to-optical link with a self-referenced microcomb,” Nat. Photonics 10, 516–520 (2016).
[Crossref]

S. B. Papp, K. Beha, P. Del’Haye, F. Quinlan, H. Lee, K. J. Vahala, and S. A. Diddams, “Microresonator frequency comb optical clock,” Optica 1, 10–14 (2014).
[Crossref]

Vig, J. R.

J. R. Vig, “Military applications of high accuracy frequency standards and clocks,” IEEE Trans. Ultrason. Ferroelectr. Freq. Control. 40, 522–527 (1993).
[Crossref]

Vogel, K. R.

S. A. Diddams, T. Udem, J. C. Bergquist, E. A. Curtis, R. E. Drullinger, L. Hollberg, W. M. Itano, W. D. Lee, C. W. Oates, K. R. Vogel, and D. J. Wineland, “An optical clock based on a single trapped 199Hg+ ion,” Science 293, 825–828 (2001).
[Crossref]

Vogt, S.

J. Grotti, S. Koller, S. Vogt, S. Häfner, U. Sterr, C. Lisdat, H. Denker, C. Voigt, L. Timmen, A. Rolland, F. N. Baynes, H. S. Margolis, M. Zampaolo, P. Thoumany, M. Pizzocaro, B. Rauf, F. Bregolin, A. Tampellini, P. Barbieri, M. Zucco, G. A. Costanzo, C. Clivati, F. Levi, and D. Calonico, “Geodesy and metrology with a transportable optical clock,” Nat. Phys. 14, 437–441 (2018).
[Crossref]

S. B. Koller, J. Grotti, S. Vogt, A. Al-Masoudi, S. Dörscher, S. Häfner, U. Sterr, and C. Lisdat, “Transportable optical lattice clock with 7×10-17 uncertainty,” Phys. Rev. Lett. 118, 073601 (2017).
[Crossref]

Voigt, C.

J. Grotti, S. Koller, S. Vogt, S. Häfner, U. Sterr, C. Lisdat, H. Denker, C. Voigt, L. Timmen, A. Rolland, F. N. Baynes, H. S. Margolis, M. Zampaolo, P. Thoumany, M. Pizzocaro, B. Rauf, F. Bregolin, A. Tampellini, P. Barbieri, M. Zucco, G. A. Costanzo, C. Clivati, F. Levi, and D. Calonico, “Geodesy and metrology with a transportable optical clock,” Nat. Phys. 14, 437–441 (2018).
[Crossref]

Volet, N.

D. T. Spencer, T. Drake, T. C. Briles, J. Stone, L. C. Sinclair, C. Fredrick, Q. Li, D. Westly, B. R. Ilic, A. Bluestone, N. Volet, T. Komljenovic, L. Chang, S. H. Lee, D. Y. Oh, M.-G. Suh, K. Y. Yang, M. H. P. Pfeiffer, T. J. Kippenberg, E. Norberg, L. Theogarajan, K. Vahala, N. R. Newbury, K. Srinivasan, J. E. Bowers, S. A. Diddams, and S. B. Papp, “An optical-frequency synthesizer using integrated photonics,” Nature 557, 81–85 (2018).
[Crossref]

Wang, C. Y.

T. Herr, V. Brasch, J. D. Jost, C. Y. Wang, N. M. Kondratiev, M. L. Gorodetsky, and T. J. Kippenberg, “Temporal solitons in optical microresonators,” Nat. Photonics 8, 145–152 (2013).
[Crossref]

Westly, D.

D. T. Spencer, T. Drake, T. C. Briles, J. Stone, L. C. Sinclair, C. Fredrick, Q. Li, D. Westly, B. R. Ilic, A. Bluestone, N. Volet, T. Komljenovic, L. Chang, S. H. Lee, D. Y. Oh, M.-G. Suh, K. Y. Yang, M. H. P. Pfeiffer, T. J. Kippenberg, E. Norberg, L. Theogarajan, K. Vahala, N. R. Newbury, K. Srinivasan, J. E. Bowers, S. A. Diddams, and S. B. Papp, “An optical-frequency synthesizer using integrated photonics,” Nature 557, 81–85 (2018).
[Crossref]

T. E. Drake, T. C. Briles, D. T. Spencer, J. R. Stone, D. R. Carlson, D. D. Hickstein, Q. Li, D. Westly, K. Srinivasan, S. A. Diddams, and S. B. Papp, “A Kerr-microresonator optical clockwork,” arXiv:1811.00581 (2018).

Westly, D. A.

Windeler, R. S.

D. J. Jones, S. A. Diddams, J. K. Ranka, A. Stentz, R. S. Windeler, J. L. Hall, and S. T. Cundiff, “Carrier-envelope phase control of femtosecond mode-locked lasers and direct optical frequency synthesis,” Science 288, 635–639 (2000).
[Crossref]

Wineland, D. J.

T. Rosenband, D. B. Hume, P. O. Schmidt, C. W. Chou, A. Brusch, L. Lorini, W. H. Oskay, R. E. Drullinger, T. M. Fortier, J. E. Stalnaker, S. A. Diddams, W. C. Swann, N. R. Newbury, W. M. Itano, D. J. Wineland, and J. C. Bergquist, “Frequency ratio of Al+ and Hg+ single-ion optical clocks; metrology at the 17th decimal place,” Science 319, 1808–1812 (2008).
[Crossref]

S. A. Diddams, T. Udem, J. C. Bergquist, E. A. Curtis, R. E. Drullinger, L. Hollberg, W. M. Itano, W. D. Lee, C. W. Oates, K. R. Vogel, and D. J. Wineland, “An optical clock based on a single trapped 199Hg+ ion,” Science 293, 825–828 (2001).
[Crossref]

Wojcik, M.

K. W. Martin, G. Phelps, N. D. Lemke, M. S. Bigelow, B. Stuhl, M. Wojcik, M. Holt, I. Coddington, M. W. Bishop, and J. H. Burke, “Compact optical atomic clock based on a two-photon transition in rubidium,” Phys. Rev. Appl. 9, 014019 (2018).
[Crossref]

Wu, J.

S. Gundavarapu, G. M. Brodnik, M. Puckett, T. Huffman, D. Bose, R. Behunin, J. Wu, T. Qiu, C. Pinho, N. Chauhan, J. Nohava, P. T. Rakich, K. D. Nelson, M. Salit, and D. J. Blumenthal, “Sub-hertz fundamental linewidth photonic integrated Brillouin laser,” Nat. Photonics 13, 60–67 (2018).
[Crossref]

Yang, K. Y.

D. T. Spencer, T. Drake, T. C. Briles, J. Stone, L. C. Sinclair, C. Fredrick, Q. Li, D. Westly, B. R. Ilic, A. Bluestone, N. Volet, T. Komljenovic, L. Chang, S. H. Lee, D. Y. Oh, M.-G. Suh, K. Y. Yang, M. H. P. Pfeiffer, T. J. Kippenberg, E. Norberg, L. Theogarajan, K. Vahala, N. R. Newbury, K. Srinivasan, J. E. Bowers, S. A. Diddams, and S. B. Papp, “An optical-frequency synthesizer using integrated photonics,” Nature 557, 81–85 (2018).
[Crossref]

X. Yi, Q.-F. Yang, X. Zhang, K. Y. Yang, X. Li, and K. Vahala, “Single-mode dispersive waves and soliton microcomb dynamics,” Nat. Commun. 8, 14869 (2017).
[Crossref]

P. Del’Haye, A. Coillet, T. Fortier, K. Beha, D. C. Cole, K. Y. Yang, H. Lee, K. J. Vahala, S. B. Papp, and S. A. Diddams, “Phase-coherent microwave-to-optical link with a self-referenced microcomb,” Nat. Photonics 10, 516–520 (2016).
[Crossref]

Yang, Q.-F.

X. Yi, Q.-F. Yang, X. Zhang, K. Y. Yang, X. Li, and K. Vahala, “Single-mode dispersive waves and soliton microcomb dynamics,” Nat. Commun. 8, 14869 (2017).
[Crossref]

Yangjin, M.

Ye, J.

Yi, X.

X. Yi, Q.-F. Yang, X. Zhang, K. Y. Yang, X. Li, and K. Vahala, “Single-mode dispersive waves and soliton microcomb dynamics,” Nat. Commun. 8, 14869 (2017).
[Crossref]

Yoon, T. H.

M. Schioppo, R. C. Brown, W. F. McGrew, N. Hinkley, R. J. Fasano, K. Beloy, T. H. Yoon, G. Milani, D. Nicolodi, J. A. Sherman, N. B. Phillips, C. W. Oates, and A. D. Ludlow, “Ultrastable optical clock with two cold-atom ensembles,” Nat. Photonics 11, 48–52 (2016).
[Crossref]

Zameroski, N. D.

N. D. Zameroski, G. D. Hager, C. J. Erickson, and J. H. Burke, “Pressure broadening and frequency shift of the 5S 1/2 to 5D 5/2 and 5S 1/2 to 7S 1/2 two photon transitions in 85Rb by the noble gases and N2,” J. Phys. B 47, 225205 (2014).
[Crossref]

Zampaolo, M.

J. Grotti, S. Koller, S. Vogt, S. Häfner, U. Sterr, C. Lisdat, H. Denker, C. Voigt, L. Timmen, A. Rolland, F. N. Baynes, H. S. Margolis, M. Zampaolo, P. Thoumany, M. Pizzocaro, B. Rauf, F. Bregolin, A. Tampellini, P. Barbieri, M. Zucco, G. A. Costanzo, C. Clivati, F. Levi, and D. Calonico, “Geodesy and metrology with a transportable optical clock,” Nat. Phys. 14, 437–441 (2018).
[Crossref]

Zervas, M.

J. Liu, A. S. Raja, M. Karpov, B. Ghadiani, M. H. P. Pfeiffer, N. J. Engelsen, H. Guo, M. Zervas, and T. J. Kippenberg, “Ultralow-power chip-based soliton microcombs for photonic integration,” Optica 5, 3–9 (2018).
[Crossref]

M. H. P. Pfeiffer, C. Herkommer, J. Liu, H. Guo, M. Karpov, E. Lucas, M. Zervas, and T. J. Kippenberg, “Octave-spanning dissipative Kerr soliton frequency combs in Si3N4 microresonators,” Optica 4, 684–690 (2017).
[Crossref]

Zhang, X.

X. Yi, Q.-F. Yang, X. Zhang, K. Y. Yang, X. Li, and K. Vahala, “Single-mode dispersive waves and soliton microcomb dynamics,” Nat. Commun. 8, 14869 (2017).
[Crossref]

Zou, C.-L.

Zucco, M.

J. Grotti, S. Koller, S. Vogt, S. Häfner, U. Sterr, C. Lisdat, H. Denker, C. Voigt, L. Timmen, A. Rolland, F. N. Baynes, H. S. Margolis, M. Zampaolo, P. Thoumany, M. Pizzocaro, B. Rauf, F. Bregolin, A. Tampellini, P. Barbieri, M. Zucco, G. A. Costanzo, C. Clivati, F. Levi, and D. Calonico, “Geodesy and metrology with a transportable optical clock,” Nat. Phys. 14, 437–441 (2018).
[Crossref]

C. Clivati, G. A. Costanzo, M. Frittelli, F. Levi, A. Mura, M. Zucco, R. Ambrosini, C. Bortolotti, F. Perini, M. Roma, and D. Calonico, “A coherent fiber link for very long baseline interferometry,” IEEE Trans. Ultrason. Ferroelectr. Freq. Control 62, 1907–1912 (2015).
[Crossref]

Appl. Opt. (1)

Appl. Phys. Lett. (1)

S. Knappe, V. Shah, P. D. D. Schwindt, L. Hollberg, J. Kitching, L. A. Liew, and J. Moreland, “A microfabricated atomic clock,” Appl. Phys. Lett. 85, 1460–1462 (2004).
[Crossref]

Comptes Rendus Phys. (1)

F. Riehle, “Towards a redefinition of the second based on optical atomic clocks,” Comptes Rendus Phys. 16, 506–515 (2015).
[Crossref]

Eur. Phys. J. Appl. Phys. (1)

L. Hilico, R. Felder, D. Touahri, O. Acef, A. Clairon, and F. Biraben, “Metrological features of the rubidium two-photon standards of the BNM-LPTF and Kastler Brossel Laboratories,” Eur. Phys. J. Appl. Phys. 4, 219–225 (1998).
[Crossref]

IEEE Trans. Instrum. Meas. (1)

C. Audoin, V. Candelier, and N. Dimarcq, “A limit to the frequency stability of passive frequency standards due to an intermodulation effect,” IEEE Trans. Instrum. Meas. 40, 121–125 (1991).
[Crossref]

IEEE Trans. Ultrason. Ferroelectr. Freq. Control (1)

C. Clivati, G. A. Costanzo, M. Frittelli, F. Levi, A. Mura, M. Zucco, R. Ambrosini, C. Bortolotti, F. Perini, M. Roma, and D. Calonico, “A coherent fiber link for very long baseline interferometry,” IEEE Trans. Ultrason. Ferroelectr. Freq. Control 62, 1907–1912 (2015).
[Crossref]

IEEE Trans. Ultrason. Ferroelectr. Freq. Control. (1)

J. R. Vig, “Military applications of high accuracy frequency standards and clocks,” IEEE Trans. Ultrason. Ferroelectr. Freq. Control. 40, 522–527 (1993).
[Crossref]

J. Lightwave Technol. (1)

J. Opt. Soc. Am. B (1)

J. Phys. (1)

F. Biraben, M. Bassini, and B. Cagnac, “Line-shapes in Doppler-free two-photon spectroscopy the effect of finite transit time,” J. Phys. 40, 445–455 (1979).
[Crossref]

J. Phys. B (1)

N. D. Zameroski, G. D. Hager, C. J. Erickson, and J. H. Burke, “Pressure broadening and frequency shift of the 5S 1/2 to 5D 5/2 and 5S 1/2 to 7S 1/2 two photon transitions in 85Rb by the noble gases and N2,” J. Phys. B 47, 225205 (2014).
[Crossref]

Light: Sci. Appl. (1)

V. Brasch, E. Lucas, J. D. Jost, M. Geiselmann, and T. J. Kippenberg, “Self-referenced photonic chip soliton Kerr frequency comb,” Light: Sci. Appl. 6, e16202 (2017).
[Crossref]

Nat. Commun. (2)

W. Liang, D. Eliyahu, V. S. Ilchenko, A. A. Savchenkov, D. Seidel, L. Maleki, and A. B. Matsko, “High spectral purity Kerr frequency comb radio frequency photonic oscillator,” Nat. Commun. 6, 1–8 (2015).
[Crossref]

X. Yi, Q.-F. Yang, X. Zhang, K. Y. Yang, X. Li, and K. Vahala, “Single-mode dispersive waves and soliton microcomb dynamics,” Nat. Commun. 8, 14869 (2017).
[Crossref]

Nat. Photonics (5)

T. Herr, V. Brasch, J. D. Jost, C. Y. Wang, N. M. Kondratiev, M. L. Gorodetsky, and T. J. Kippenberg, “Temporal solitons in optical microresonators,” Nat. Photonics 8, 145–152 (2013).
[Crossref]

P. Del’Haye, A. Coillet, T. Fortier, K. Beha, D. C. Cole, K. Y. Yang, H. Lee, K. J. Vahala, S. B. Papp, and S. A. Diddams, “Phase-coherent microwave-to-optical link with a self-referenced microcomb,” Nat. Photonics 10, 516–520 (2016).
[Crossref]

M. Schioppo, R. C. Brown, W. F. McGrew, N. Hinkley, R. J. Fasano, K. Beloy, T. H. Yoon, G. Milani, D. Nicolodi, J. A. Sherman, N. B. Phillips, C. W. Oates, and A. D. Ludlow, “Ultrastable optical clock with two cold-atom ensembles,” Nat. Photonics 11, 48–52 (2016).
[Crossref]

F. Riehle, “Optical clock networks,” Nat. Photonics 11, 25–31 (2017).
[Crossref]

S. Gundavarapu, G. M. Brodnik, M. Puckett, T. Huffman, D. Bose, R. Behunin, J. Wu, T. Qiu, C. Pinho, N. Chauhan, J. Nohava, P. T. Rakich, K. D. Nelson, M. Salit, and D. J. Blumenthal, “Sub-hertz fundamental linewidth photonic integrated Brillouin laser,” Nat. Photonics 13, 60–67 (2018).
[Crossref]

Nat. Phys. (1)

J. Grotti, S. Koller, S. Vogt, S. Häfner, U. Sterr, C. Lisdat, H. Denker, C. Voigt, L. Timmen, A. Rolland, F. N. Baynes, H. S. Margolis, M. Zampaolo, P. Thoumany, M. Pizzocaro, B. Rauf, F. Bregolin, A. Tampellini, P. Barbieri, M. Zucco, G. A. Costanzo, C. Clivati, F. Levi, and D. Calonico, “Geodesy and metrology with a transportable optical clock,” Nat. Phys. 14, 437–441 (2018).
[Crossref]

Nature (2)

B. Stern, X. Ji, Y. Okawachi, A. L. Gaeta, and M. Lipson, “Battery-operated integrated frequency comb generator,” Nature 562, 401–405 (2018).
[Crossref]

D. T. Spencer, T. Drake, T. C. Briles, J. Stone, L. C. Sinclair, C. Fredrick, Q. Li, D. Westly, B. R. Ilic, A. Bluestone, N. Volet, T. Komljenovic, L. Chang, S. H. Lee, D. Y. Oh, M.-G. Suh, K. Y. Yang, M. H. P. Pfeiffer, T. J. Kippenberg, E. Norberg, L. Theogarajan, K. Vahala, N. R. Newbury, K. Srinivasan, J. E. Bowers, S. A. Diddams, and S. B. Papp, “An optical-frequency synthesizer using integrated photonics,” Nature 557, 81–85 (2018).
[Crossref]

Opt. Commun. (1)

J. E. Bernard, A. A. Madej, K. J. Siemsen, L. Marmet, C. Latrasse, D. Touahri, M. Poulin, M. Allard, and M. Tetu, “Absolute frequency measurement of a laser at 1556  nm locked to the 5S1/2-5D5/2 two-photon transition in 87-Rb,” Opt. Commun. 173, 357–364 (2000).
[Crossref]

Opt. Express (1)

Opt. Lett. (3)

Optica (7)

M. T. Hummon, S. Kang, D. G. Bopp, Q. Li, D. A. Westly, S. Kim, C. Fredrick, S. A. Diddams, K. Srinivasan, V. Aksyuk, and J. E. Kitching, “Photonic chip for laser stabilization to an atomic vapor with 10-11 instability,” Optica 5, 443–449 (2018).
[Crossref]

S. B. Papp, K. Beha, P. Del’Haye, F. Quinlan, H. Lee, K. J. Vahala, and S. A. Diddams, “Microresonator frequency comb optical clock,” Optica 1, 10–14 (2014).
[Crossref]

Q. Li, T. C. Briles, D. A. Westly, T. E. Drake, J. R. Stone, B. R. Ilic, S. A. Diddams, S. B. Papp, and K. Srinivasan, “Stably accessing octave-spanning microresonator frequency combs in the soliton regime,” Optica 4, 193–203 (2016).
[Crossref]

M. H. P. Pfeiffer, C. Herkommer, J. Liu, H. Guo, M. Karpov, E. Lucas, M. Zervas, and T. J. Kippenberg, “Octave-spanning dissipative Kerr soliton frequency combs in Si3N4 microresonators,” Optica 4, 684–690 (2017).
[Crossref]

J. D. Jost, T. Herr, C. Lecaplain, V. Brasch, M. H. P. Pfeiffer, and T. J. Kippenberg, “Counting the cycles of light using a self-referenced optical microresonator,” Optica 2, 706–711 (2015).
[Crossref]

J. Liu, A. S. Raja, M. Karpov, B. Ghadiani, M. H. P. Pfeiffer, N. J. Engelsen, H. Guo, M. Zervas, and T. J. Kippenberg, “Ultralow-power chip-based soliton microcombs for photonic integration,” Optica 5, 3–9 (2018).
[Crossref]

X. Guo, C.-L. Zou, and H. X. Tang, “Second-harmonic generation in aluminum nitride microrings with 2500%/W conversion efficiency,” Optica 3, 1126–1131 (2016).
[Crossref]

Phys. Rev. Appl. (1)

K. W. Martin, G. Phelps, N. D. Lemke, M. S. Bigelow, B. Stuhl, M. Wojcik, M. Holt, I. Coddington, M. W. Bishop, and J. H. Burke, “Compact optical atomic clock based on a two-photon transition in rubidium,” Phys. Rev. Appl. 9, 014019 (2018).
[Crossref]

Phys. Rev. Lett. (3)

S. B. Koller, J. Grotti, S. Vogt, A. Al-Masoudi, S. Dörscher, S. Häfner, U. Sterr, and C. Lisdat, “Transportable optical lattice clock with 7×10-17 uncertainty,” Phys. Rev. Lett. 118, 073601 (2017).
[Crossref]

R. M. Godun, P. B. R. Nisbet-Jones, J. M. Jones, S. A. King, L. A. M. Johnson, H. S. Margolis, K. Szymaniec, S. N. Lea, K. Bongs, and P. Gill, “Frequency ratio of two optical clock transitions in 171Yb+ and constraints on the time variation of fundamental constants,” Phys. Rev. Lett. 113, 210801 (2014).
[Crossref]

J. R. Stone, T. C. Briles, T. E. Drake, D. T. Spencer, D. R. Carlson, S. A. Diddams, and S. B. Papp, “Thermal and nonlinear dissipative-soliton dynamics in Kerr-microresonator frequency combs,” Phys. Rev. Lett. 121, 63902 (2018).
[Crossref]

Rep. Prog. Phys. (1)

G. Grynberg and B. Cagnac, “Doppler-free multiphotonic spectroscopy,” Rep. Prog. Phys. 40, 791–841 (1977).
[Crossref]

Science (4)

D. J. Jones, S. A. Diddams, J. K. Ranka, A. Stentz, R. S. Windeler, J. L. Hall, and S. T. Cundiff, “Carrier-envelope phase control of femtosecond mode-locked lasers and direct optical frequency synthesis,” Science 288, 635–639 (2000).
[Crossref]

S. A. Diddams, T. Udem, J. C. Bergquist, E. A. Curtis, R. E. Drullinger, L. Hollberg, W. M. Itano, W. D. Lee, C. W. Oates, K. R. Vogel, and D. J. Wineland, “An optical clock based on a single trapped 199Hg+ ion,” Science 293, 825–828 (2001).
[Crossref]

T. Rosenband, D. B. Hume, P. O. Schmidt, C. W. Chou, A. Brusch, L. Lorini, W. H. Oskay, R. E. Drullinger, T. M. Fortier, J. E. Stalnaker, S. A. Diddams, W. C. Swann, N. R. Newbury, W. M. Itano, D. J. Wineland, and J. C. Bergquist, “Frequency ratio of Al+ and Hg+ single-ion optical clocks; metrology at the 17th decimal place,” Science 319, 1808–1812 (2008).
[Crossref]

T. J. Kippenberg, A. L. Gaeta, M. Lipson, and M. L. Gorodetsky, “Dissipative Kerr solitons in optical microresonators,” Science 361, eaan8083 (2018).
[Crossref]

Other (1)

T. E. Drake, T. C. Briles, D. T. Spencer, J. R. Stone, D. R. Carlson, D. D. Hickstein, Q. Li, D. Westly, K. Srinivasan, S. A. Diddams, and S. B. Papp, “A Kerr-microresonator optical clockwork,” arXiv:1811.00581 (2018).

Supplementary Material (1)

NameDescription
Supplement 1       Supplementary Text

Cited By

Optica participates in Crossref's Cited-By Linking service. Citing articles from Optica Publishing Group journals and other participating publishers are listed here.

Alert me when this article is cited.


Figures (4)

Fig. 1.
Fig. 1. Schematic of the microfabricated photonic optical atomic clock. (a) The microfabricated optical clock consists of an optical local oscillator, a microfabricated Rb vapor cell, and a pair of microresonator frequency combs, which serve as optical clockwork. Absorption of the clock laser in the cell is detected via the collection of 420 nm fluorescence using a microfabricated PMT. The optical clockwork consists of interlocked DKS combs generated using a 2 mm diameter, silica microresonator, and a 46 μm diameter, SiN microresonator. Stabilization of the frequency combs’ output is performed via electronic feedback (indicated by dotted lines) to the pump frequency and resonator detuning of the ECDLs used to pump the microresonators. The feedback signals are generated from optical heterodyne beat notes of adjacent comb teeth, as indicated by the solid black arrows. In some cases, frequency doubling (dashed black arrows) was required to compare optical signals. For simplicity, we do not picture the frequency and intensity modulators used for feedback in the comb frequency servo loops. (b) Scanning-electron microscope image of the SiN microresonator. Photographs of (c) the silica microresonator and (d) the microfabricated Rb vapor cell.
Fig. 2.
Fig. 2. Spectroscopy of optical clock transition. Doppler-free fluorescence spectroscopy of the optical clock transition between the 5 S 1 / 2 , F = 2 to 5 D 5 / 2 , F = 4 levels at 385.284566 THz, with a full width at half-maximum of 1 MHz . The atomic level structure of the 87Rb two-photon transition is shown as an inset.
Fig. 3.
Fig. 3. Microcomb spectra. (a) SiN microresonator comb spectrum, showing the 1 THz comb tooth spacing with a resolution bandwidth of Δ λ = 0.1 nm . An f - 2 f interferometer (light blue arrow) in which light at 1998 nm is frequency-doubled to heterodyne with the comb teeth in the dispersive wave at 999 nm is used to measure and stabilize the offset frequency, f ceo , of the SiN comb ( δ = f ceo / 10 MHz ). (b) Silica microresonator comb spectrum (light blue) with 22 GHz repetition rate, shown overlaid with three teeth from the 1 THz, SiN comb (dark blue), with a resolution of Δ λ = 0.02 nm . Arrows indicate phase locks used to stabilize the combs. Greek letters show the ratio-of-integer values multiplied by a 10 MHz clock that are used as a reference for each of the phase locks. For the devices used in the experiment, α = 154.224 , β = 3525.29238 , γ = 539.9808 , and δ = 1280.0 . (c) RF spectrum of the 22 GHz clock output.
Fig. 4.
Fig. 4. Optical clock performance. (a) Time-series measurement of the clock optical frequency offset derived from the 22 GHz clock output frequency, v clock , opt (top, blue) and derived from the beat note against the Er:fiber frequency comb, v laser (bottom, orange). The reference frequency is ν o = 385284566370400 Hz [34]. Short breaks in the data indicate periods where the clock laser dropped out of lock. (b) Comparison of Allan deviation of 22 GHz clock output for the free-running silica microresonator (green open squares), the fully stabilized comb (blue circles), and the heterodyne beat note of the clock laser with the Er:fiber comb (orange triangles). At long integration times (purple pentagons), the clock stability is limited to 1 × 10 13 due to temperature fluctuations in the lab. Error bars represent a 68% confidence interval. An Allan deviation of a Microsemi chip-scale atomic clock (CSAC) measured against a hydrogen maser is shown for comparison (gray circles). (c) Frequency noise spectra for the free-running and locked clock laser. A large servo bump at 4 kHz is evidence of frequency noise spectra. (d) Phase noise away from carrier for the 22 GHz clock output signal (blue), along with the contributions from the intermediate phase locks (red and magenta) and the phase noise of the clock laser calculated from the laser frequency noise spectrum (orange dashed), which gives a lower limit on the phase noise of the 22 GHz clock output.

Equations (1)

Equations on this page are rendered with MathJax. Learn more.

f GHz , rep = v Rb + ( α / 2 + 2 · [ ( q 1 ) · β + q · γ δ ] ) · f 10 MHz 2 · q · p ,

Metrics