Abstract

Most swept external cavity diode lasers tune in the short-to-long wavelength direction (red tuning). Lower relative intensity noise (RIN) and higher output power are typically possible in this direction. We show here that long-to-short tuning (blue tuning) is possible for a short, linear cavity laser that has both low noise and high power. This mode of operation is made possible by nonlinear frequency broadening in the semiconductor optical amplifier (SOA) followed by clipping of the red portion of the spectrum by the micro-electro-mechanical systems (MEMS) tunable Fabry-Perot filter. Blue shifting during gain recovery is an important broadening mechanism. There is an approximate 50% advantage in coherence length for the same filter bandwidth for blue over red tuning, which allows deeper imaging in optical coherence tomography (OCT) applications. Calculations contrasting the blue tuning mechanism with red tuning are presented. The accuracy of the blue-tuning model is confirmed by coherence and coherence revival measurements and simulations.

© 2018 Optical Society of America under the terms of the OSA Open Access Publishing Agreement

Full Article  |  PDF Article
OSA Recommended Articles
Coherence properties of short cavity swept lasers

Bart Johnson, Walid Atia, Mark Kuznetsov, Brian D. Goldberg, Peter Whitney, and Dale C. Flanders
Biomed. Opt. Express 8(2) 1045-1055 (2017)

High-speed OCT light sources and systems [Invited]

Thomas Klein and Robert Huber
Biomed. Opt. Express 8(2) 828-859 (2017)

Balance of physical effects causing stationary operation of Fourier domain mode-locked lasers

Sebastian Todor, Benjamin Biedermann, Robert Huber, and Christian Jirauschek
J. Opt. Soc. Am. B 29(4) 656-664 (2012)

References

  • View by:
  • |
  • |
  • |

  1. M. Choma, M. Sarunic, C. Yang, and J. Izatt, “Sensitivity advantage of swept source and Fourier domain optical coherence tomography,” Opt. Express 11, 2183–2189 (2003).
    [Crossref] [PubMed]
  2. R. Leitgeb, C. K. Hitzenberger, and A. F. Fercher, “Performance of Fourier domain vs. time domain optical coherence tomography,” Opt. Express 11, 889–894 (2003).
    [Crossref] [PubMed]
  3. J. de Boer, B. Cense, B. Park, M. Pierce, G. Tearney, and B. Bouma, “Improved signal-to-noise ratio in spectral-domain compared with time-domain optical coherence tomography,” Opt. Lett. 28, 2067–2069 (2003).
    [Crossref] [PubMed]
  4. S. Yun, G. Tearney, J. de Boer, N. Iftimia, and B. Bouma, “High-speed optical frequency-domain imaging,” Opt. Express 11, 2953–2963 (2003).
    [Crossref] [PubMed]
  5. A. Bilenca, S. H. Yun, G. J. Tearney, and B. E. Bouma, “Numerical study of wavelength-swept semiconductor ring lasers: the role of refractive-index nonlinearities in semiconductor optical amplifiers and implications for biomedical imaging applications,” Opt. Lett. 31, 760–762 (2006).
    [Crossref] [PubMed]
  6. B. Johnson, W. Atia, M. Kuznetsov, B. D. Goldberg, P. Whitney, and D. C. Flanders, “Analysis of a spinning polygon wavelength swept laser,” (2015). ArXiv:1501.07003v2.
  7. M. Kuznetsov, W. Atia, B. Johnson, and D. C. Flanders, “Compact ultrafast reflective Fabry-Perot tunable lasers for OCT imaging applications,” Proc. SPIE 7554, 75541F (2010).
  8. B. C. Johnson, W. Atia, M. Kuznetsov, and D. C. Flanders, “Passively mode locked swept lasers,” (2013). Photonics West, Poster 8571-103, electronic copy available from authors.
  9. B. Johnson, W. Atia, M. Kuznetsov, B. Goldberg, P. Whitney, and D. Flanders, “Coherence properties of short cavity swept lasers,” Biomed. Opt. Express 8, 1045–1055 (2017).
    [Crossref] [PubMed]
  10. B. Johnson, W. Atia, M. Kuznetsov, C. Cook, B. Goldberg, B. Wells, N. Larson, E. McKenzie, C. Melendez, E. Mallon, S. Woo, R. Murdza, P. Whitney, and D. Flanders, “Swept light sources,” in Optical Coherence Tomography, Second Edition, W. Drexler and J. Fujimoto, eds. (Springer Reference, 2015), pp. 639–658.
    [Crossref]
  11. D. C. Flanders, M. E. Kuznetsov, and W. A. Atia, “Laser with tilted multi spatial mode resonator tuning element,” (2008). US Patent 7,415,049.
  12. B. Johnson and D. Flanders, “Actively mode locked laser swept source for OCT medical imaging,” (2010). US Patent Application 12/979225.
  13. S. Slepneva, B. O’Shaughnessy, B. Kelleher, S. P. Hegarty, A. Vladimirov, H.-C. Lyu, K. Karnowski, M. Wojtkowski, and G. Huyet, “Dynamics of a short cavity swept source OCT laser,” Opt. Express 22, 18177–18185 (2014).
    [Crossref] [PubMed]
  14. E. Avrutin and L. Zhang, “Dynamics of semiconductor lasers under fast intracavity frequency sweeping,” 14th Int. Conf. on Transparent Opt. Networks (ICTON) pp. 1–4 (2012).
  15. M. Duelk and K. Hsu, “SLEDs and swept source laser technology for OCT,” in Optical Coherence Tomography, Second Edition, W. Drexler and J. Fujimoto, eds. (Springer Reference, 2015), pp. 527–561.
    [Crossref]
  16. C. Chong, T. Suzuki, A. Morosawa, and T. Sakai, “Spectral narrowing effect by quasi-phase continuous tuning in high-speed wavelength-swept light source,” Opt. Express 16, 21105–21118 (2008).
    [Crossref] [PubMed]
  17. C. H. Henry, “Theory of the linewidth of semiconductor lasers,” IEEE J. Quantum Electron. QE-18, 259–264 (1982).
    [Crossref]
  18. A. Dhalla, D. Nankivil, and J. A. Izatt, “Complex conjugate resolved heterodyne swept source optical coherence tomography using coherence revival,” Biomed. Opt. Express 3, 633–649 (2012).
    [Crossref] [PubMed]
  19. S.-Y. Baek, O. Kwon, and Y.-H. Kim, “High-resolution mode-spacing measurement of the blue-violet diode laser using interference of fields created with time delays greater than the coherence time,” Jpn. J. Appl. Phys. 46, 7720–7723 (2007).
    [Crossref]
  20. A. Bradu, S. Rivet, and A. Podoleanu, “Master/slave interferometry – ideal tool for coherence revival swept source optical coherence tomography,” Biomed. Opt. Express 7, 2453–2468 (2016).
    [Crossref] [PubMed]

2017 (1)

2016 (1)

2014 (1)

2012 (1)

2010 (1)

M. Kuznetsov, W. Atia, B. Johnson, and D. C. Flanders, “Compact ultrafast reflective Fabry-Perot tunable lasers for OCT imaging applications,” Proc. SPIE 7554, 75541F (2010).

2008 (1)

2007 (1)

S.-Y. Baek, O. Kwon, and Y.-H. Kim, “High-resolution mode-spacing measurement of the blue-violet diode laser using interference of fields created with time delays greater than the coherence time,” Jpn. J. Appl. Phys. 46, 7720–7723 (2007).
[Crossref]

2006 (1)

2003 (4)

1982 (1)

C. H. Henry, “Theory of the linewidth of semiconductor lasers,” IEEE J. Quantum Electron. QE-18, 259–264 (1982).
[Crossref]

Atia, W.

B. Johnson, W. Atia, M. Kuznetsov, B. Goldberg, P. Whitney, and D. Flanders, “Coherence properties of short cavity swept lasers,” Biomed. Opt. Express 8, 1045–1055 (2017).
[Crossref] [PubMed]

M. Kuznetsov, W. Atia, B. Johnson, and D. C. Flanders, “Compact ultrafast reflective Fabry-Perot tunable lasers for OCT imaging applications,” Proc. SPIE 7554, 75541F (2010).

B. Johnson, W. Atia, M. Kuznetsov, B. D. Goldberg, P. Whitney, and D. C. Flanders, “Analysis of a spinning polygon wavelength swept laser,” (2015). ArXiv:1501.07003v2.

B. C. Johnson, W. Atia, M. Kuznetsov, and D. C. Flanders, “Passively mode locked swept lasers,” (2013). Photonics West, Poster 8571-103, electronic copy available from authors.

B. Johnson, W. Atia, M. Kuznetsov, C. Cook, B. Goldberg, B. Wells, N. Larson, E. McKenzie, C. Melendez, E. Mallon, S. Woo, R. Murdza, P. Whitney, and D. Flanders, “Swept light sources,” in Optical Coherence Tomography, Second Edition, W. Drexler and J. Fujimoto, eds. (Springer Reference, 2015), pp. 639–658.
[Crossref]

Atia, W. A.

D. C. Flanders, M. E. Kuznetsov, and W. A. Atia, “Laser with tilted multi spatial mode resonator tuning element,” (2008). US Patent 7,415,049.

Avrutin, E.

E. Avrutin and L. Zhang, “Dynamics of semiconductor lasers under fast intracavity frequency sweeping,” 14th Int. Conf. on Transparent Opt. Networks (ICTON) pp. 1–4 (2012).

Baek, S.-Y.

S.-Y. Baek, O. Kwon, and Y.-H. Kim, “High-resolution mode-spacing measurement of the blue-violet diode laser using interference of fields created with time delays greater than the coherence time,” Jpn. J. Appl. Phys. 46, 7720–7723 (2007).
[Crossref]

Bilenca, A.

Bouma, B.

Bouma, B. E.

Bradu, A.

Cense, B.

Choma, M.

Chong, C.

Cook, C.

B. Johnson, W. Atia, M. Kuznetsov, C. Cook, B. Goldberg, B. Wells, N. Larson, E. McKenzie, C. Melendez, E. Mallon, S. Woo, R. Murdza, P. Whitney, and D. Flanders, “Swept light sources,” in Optical Coherence Tomography, Second Edition, W. Drexler and J. Fujimoto, eds. (Springer Reference, 2015), pp. 639–658.
[Crossref]

de Boer, J.

Dhalla, A.

Duelk, M.

M. Duelk and K. Hsu, “SLEDs and swept source laser technology for OCT,” in Optical Coherence Tomography, Second Edition, W. Drexler and J. Fujimoto, eds. (Springer Reference, 2015), pp. 527–561.
[Crossref]

Fercher, A. F.

Flanders, D.

B. Johnson, W. Atia, M. Kuznetsov, B. Goldberg, P. Whitney, and D. Flanders, “Coherence properties of short cavity swept lasers,” Biomed. Opt. Express 8, 1045–1055 (2017).
[Crossref] [PubMed]

B. Johnson and D. Flanders, “Actively mode locked laser swept source for OCT medical imaging,” (2010). US Patent Application 12/979225.

B. Johnson, W. Atia, M. Kuznetsov, C. Cook, B. Goldberg, B. Wells, N. Larson, E. McKenzie, C. Melendez, E. Mallon, S. Woo, R. Murdza, P. Whitney, and D. Flanders, “Swept light sources,” in Optical Coherence Tomography, Second Edition, W. Drexler and J. Fujimoto, eds. (Springer Reference, 2015), pp. 639–658.
[Crossref]

Flanders, D. C.

M. Kuznetsov, W. Atia, B. Johnson, and D. C. Flanders, “Compact ultrafast reflective Fabry-Perot tunable lasers for OCT imaging applications,” Proc. SPIE 7554, 75541F (2010).

B. C. Johnson, W. Atia, M. Kuznetsov, and D. C. Flanders, “Passively mode locked swept lasers,” (2013). Photonics West, Poster 8571-103, electronic copy available from authors.

B. Johnson, W. Atia, M. Kuznetsov, B. D. Goldberg, P. Whitney, and D. C. Flanders, “Analysis of a spinning polygon wavelength swept laser,” (2015). ArXiv:1501.07003v2.

D. C. Flanders, M. E. Kuznetsov, and W. A. Atia, “Laser with tilted multi spatial mode resonator tuning element,” (2008). US Patent 7,415,049.

Goldberg, B.

B. Johnson, W. Atia, M. Kuznetsov, B. Goldberg, P. Whitney, and D. Flanders, “Coherence properties of short cavity swept lasers,” Biomed. Opt. Express 8, 1045–1055 (2017).
[Crossref] [PubMed]

B. Johnson, W. Atia, M. Kuznetsov, C. Cook, B. Goldberg, B. Wells, N. Larson, E. McKenzie, C. Melendez, E. Mallon, S. Woo, R. Murdza, P. Whitney, and D. Flanders, “Swept light sources,” in Optical Coherence Tomography, Second Edition, W. Drexler and J. Fujimoto, eds. (Springer Reference, 2015), pp. 639–658.
[Crossref]

Goldberg, B. D.

B. Johnson, W. Atia, M. Kuznetsov, B. D. Goldberg, P. Whitney, and D. C. Flanders, “Analysis of a spinning polygon wavelength swept laser,” (2015). ArXiv:1501.07003v2.

Hegarty, S. P.

Henry, C. H.

C. H. Henry, “Theory of the linewidth of semiconductor lasers,” IEEE J. Quantum Electron. QE-18, 259–264 (1982).
[Crossref]

Hitzenberger, C. K.

Hsu, K.

M. Duelk and K. Hsu, “SLEDs and swept source laser technology for OCT,” in Optical Coherence Tomography, Second Edition, W. Drexler and J. Fujimoto, eds. (Springer Reference, 2015), pp. 527–561.
[Crossref]

Huyet, G.

Iftimia, N.

Izatt, J.

Izatt, J. A.

Johnson, B.

B. Johnson, W. Atia, M. Kuznetsov, B. Goldberg, P. Whitney, and D. Flanders, “Coherence properties of short cavity swept lasers,” Biomed. Opt. Express 8, 1045–1055 (2017).
[Crossref] [PubMed]

M. Kuznetsov, W. Atia, B. Johnson, and D. C. Flanders, “Compact ultrafast reflective Fabry-Perot tunable lasers for OCT imaging applications,” Proc. SPIE 7554, 75541F (2010).

B. Johnson, W. Atia, M. Kuznetsov, C. Cook, B. Goldberg, B. Wells, N. Larson, E. McKenzie, C. Melendez, E. Mallon, S. Woo, R. Murdza, P. Whitney, and D. Flanders, “Swept light sources,” in Optical Coherence Tomography, Second Edition, W. Drexler and J. Fujimoto, eds. (Springer Reference, 2015), pp. 639–658.
[Crossref]

B. Johnson and D. Flanders, “Actively mode locked laser swept source for OCT medical imaging,” (2010). US Patent Application 12/979225.

B. Johnson, W. Atia, M. Kuznetsov, B. D. Goldberg, P. Whitney, and D. C. Flanders, “Analysis of a spinning polygon wavelength swept laser,” (2015). ArXiv:1501.07003v2.

Johnson, B. C.

B. C. Johnson, W. Atia, M. Kuznetsov, and D. C. Flanders, “Passively mode locked swept lasers,” (2013). Photonics West, Poster 8571-103, electronic copy available from authors.

Karnowski, K.

Kelleher, B.

Kim, Y.-H.

S.-Y. Baek, O. Kwon, and Y.-H. Kim, “High-resolution mode-spacing measurement of the blue-violet diode laser using interference of fields created with time delays greater than the coherence time,” Jpn. J. Appl. Phys. 46, 7720–7723 (2007).
[Crossref]

Kuznetsov, M.

B. Johnson, W. Atia, M. Kuznetsov, B. Goldberg, P. Whitney, and D. Flanders, “Coherence properties of short cavity swept lasers,” Biomed. Opt. Express 8, 1045–1055 (2017).
[Crossref] [PubMed]

M. Kuznetsov, W. Atia, B. Johnson, and D. C. Flanders, “Compact ultrafast reflective Fabry-Perot tunable lasers for OCT imaging applications,” Proc. SPIE 7554, 75541F (2010).

B. Johnson, W. Atia, M. Kuznetsov, B. D. Goldberg, P. Whitney, and D. C. Flanders, “Analysis of a spinning polygon wavelength swept laser,” (2015). ArXiv:1501.07003v2.

B. C. Johnson, W. Atia, M. Kuznetsov, and D. C. Flanders, “Passively mode locked swept lasers,” (2013). Photonics West, Poster 8571-103, electronic copy available from authors.

B. Johnson, W. Atia, M. Kuznetsov, C. Cook, B. Goldberg, B. Wells, N. Larson, E. McKenzie, C. Melendez, E. Mallon, S. Woo, R. Murdza, P. Whitney, and D. Flanders, “Swept light sources,” in Optical Coherence Tomography, Second Edition, W. Drexler and J. Fujimoto, eds. (Springer Reference, 2015), pp. 639–658.
[Crossref]

Kuznetsov, M. E.

D. C. Flanders, M. E. Kuznetsov, and W. A. Atia, “Laser with tilted multi spatial mode resonator tuning element,” (2008). US Patent 7,415,049.

Kwon, O.

S.-Y. Baek, O. Kwon, and Y.-H. Kim, “High-resolution mode-spacing measurement of the blue-violet diode laser using interference of fields created with time delays greater than the coherence time,” Jpn. J. Appl. Phys. 46, 7720–7723 (2007).
[Crossref]

Larson, N.

B. Johnson, W. Atia, M. Kuznetsov, C. Cook, B. Goldberg, B. Wells, N. Larson, E. McKenzie, C. Melendez, E. Mallon, S. Woo, R. Murdza, P. Whitney, and D. Flanders, “Swept light sources,” in Optical Coherence Tomography, Second Edition, W. Drexler and J. Fujimoto, eds. (Springer Reference, 2015), pp. 639–658.
[Crossref]

Leitgeb, R.

Lyu, H.-C.

Mallon, E.

B. Johnson, W. Atia, M. Kuznetsov, C. Cook, B. Goldberg, B. Wells, N. Larson, E. McKenzie, C. Melendez, E. Mallon, S. Woo, R. Murdza, P. Whitney, and D. Flanders, “Swept light sources,” in Optical Coherence Tomography, Second Edition, W. Drexler and J. Fujimoto, eds. (Springer Reference, 2015), pp. 639–658.
[Crossref]

McKenzie, E.

B. Johnson, W. Atia, M. Kuznetsov, C. Cook, B. Goldberg, B. Wells, N. Larson, E. McKenzie, C. Melendez, E. Mallon, S. Woo, R. Murdza, P. Whitney, and D. Flanders, “Swept light sources,” in Optical Coherence Tomography, Second Edition, W. Drexler and J. Fujimoto, eds. (Springer Reference, 2015), pp. 639–658.
[Crossref]

Melendez, C.

B. Johnson, W. Atia, M. Kuznetsov, C. Cook, B. Goldberg, B. Wells, N. Larson, E. McKenzie, C. Melendez, E. Mallon, S. Woo, R. Murdza, P. Whitney, and D. Flanders, “Swept light sources,” in Optical Coherence Tomography, Second Edition, W. Drexler and J. Fujimoto, eds. (Springer Reference, 2015), pp. 639–658.
[Crossref]

Morosawa, A.

Murdza, R.

B. Johnson, W. Atia, M. Kuznetsov, C. Cook, B. Goldberg, B. Wells, N. Larson, E. McKenzie, C. Melendez, E. Mallon, S. Woo, R. Murdza, P. Whitney, and D. Flanders, “Swept light sources,” in Optical Coherence Tomography, Second Edition, W. Drexler and J. Fujimoto, eds. (Springer Reference, 2015), pp. 639–658.
[Crossref]

Nankivil, D.

O’Shaughnessy, B.

Park, B.

Pierce, M.

Podoleanu, A.

Rivet, S.

Sakai, T.

Sarunic, M.

Slepneva, S.

Suzuki, T.

Tearney, G.

Tearney, G. J.

Vladimirov, A.

Wells, B.

B. Johnson, W. Atia, M. Kuznetsov, C. Cook, B. Goldberg, B. Wells, N. Larson, E. McKenzie, C. Melendez, E. Mallon, S. Woo, R. Murdza, P. Whitney, and D. Flanders, “Swept light sources,” in Optical Coherence Tomography, Second Edition, W. Drexler and J. Fujimoto, eds. (Springer Reference, 2015), pp. 639–658.
[Crossref]

Whitney, P.

B. Johnson, W. Atia, M. Kuznetsov, B. Goldberg, P. Whitney, and D. Flanders, “Coherence properties of short cavity swept lasers,” Biomed. Opt. Express 8, 1045–1055 (2017).
[Crossref] [PubMed]

B. Johnson, W. Atia, M. Kuznetsov, C. Cook, B. Goldberg, B. Wells, N. Larson, E. McKenzie, C. Melendez, E. Mallon, S. Woo, R. Murdza, P. Whitney, and D. Flanders, “Swept light sources,” in Optical Coherence Tomography, Second Edition, W. Drexler and J. Fujimoto, eds. (Springer Reference, 2015), pp. 639–658.
[Crossref]

B. Johnson, W. Atia, M. Kuznetsov, B. D. Goldberg, P. Whitney, and D. C. Flanders, “Analysis of a spinning polygon wavelength swept laser,” (2015). ArXiv:1501.07003v2.

Wojtkowski, M.

Woo, S.

B. Johnson, W. Atia, M. Kuznetsov, C. Cook, B. Goldberg, B. Wells, N. Larson, E. McKenzie, C. Melendez, E. Mallon, S. Woo, R. Murdza, P. Whitney, and D. Flanders, “Swept light sources,” in Optical Coherence Tomography, Second Edition, W. Drexler and J. Fujimoto, eds. (Springer Reference, 2015), pp. 639–658.
[Crossref]

Yang, C.

Yun, S.

Yun, S. H.

Zhang, L.

E. Avrutin and L. Zhang, “Dynamics of semiconductor lasers under fast intracavity frequency sweeping,” 14th Int. Conf. on Transparent Opt. Networks (ICTON) pp. 1–4 (2012).

Biomed. Opt. Express (3)

IEEE J. Quantum Electron. (1)

C. H. Henry, “Theory of the linewidth of semiconductor lasers,” IEEE J. Quantum Electron. QE-18, 259–264 (1982).
[Crossref]

Jpn. J. Appl. Phys. (1)

S.-Y. Baek, O. Kwon, and Y.-H. Kim, “High-resolution mode-spacing measurement of the blue-violet diode laser using interference of fields created with time delays greater than the coherence time,” Jpn. J. Appl. Phys. 46, 7720–7723 (2007).
[Crossref]

Opt. Express (5)

Opt. Lett. (2)

Proc. SPIE (1)

M. Kuznetsov, W. Atia, B. Johnson, and D. C. Flanders, “Compact ultrafast reflective Fabry-Perot tunable lasers for OCT imaging applications,” Proc. SPIE 7554, 75541F (2010).

Other (7)

B. C. Johnson, W. Atia, M. Kuznetsov, and D. C. Flanders, “Passively mode locked swept lasers,” (2013). Photonics West, Poster 8571-103, electronic copy available from authors.

E. Avrutin and L. Zhang, “Dynamics of semiconductor lasers under fast intracavity frequency sweeping,” 14th Int. Conf. on Transparent Opt. Networks (ICTON) pp. 1–4 (2012).

M. Duelk and K. Hsu, “SLEDs and swept source laser technology for OCT,” in Optical Coherence Tomography, Second Edition, W. Drexler and J. Fujimoto, eds. (Springer Reference, 2015), pp. 527–561.
[Crossref]

B. Johnson, W. Atia, M. Kuznetsov, B. D. Goldberg, P. Whitney, and D. C. Flanders, “Analysis of a spinning polygon wavelength swept laser,” (2015). ArXiv:1501.07003v2.

B. Johnson, W. Atia, M. Kuznetsov, C. Cook, B. Goldberg, B. Wells, N. Larson, E. McKenzie, C. Melendez, E. Mallon, S. Woo, R. Murdza, P. Whitney, and D. Flanders, “Swept light sources,” in Optical Coherence Tomography, Second Edition, W. Drexler and J. Fujimoto, eds. (Springer Reference, 2015), pp. 639–658.
[Crossref]

D. C. Flanders, M. E. Kuznetsov, and W. A. Atia, “Laser with tilted multi spatial mode resonator tuning element,” (2008). US Patent 7,415,049.

B. Johnson and D. Flanders, “Actively mode locked laser swept source for OCT medical imaging,” (2010). US Patent Application 12/979225.

Cited By

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

Alert me when this article is cited.


Figures (10)

Fig. 1
Fig. 1 Rapidly red tuning a short cavity laser causes it to mode lock. The pulses deplete the gain and cause the index to rise. This red shifts the light field, causing the laser to “hop” to a longer wavelength on each trip around the cavity.
Fig. 2
Fig. 2 Diagram of the blue-tuning laser cavity, which is similar to that of the red tuning laser.
Fig. 3
Fig. 3 Laser sweep analysis. The clock interferometer frequency (a) is for a clock set for a 6.0mm Nyquist depth. The blue power trace (c) shows pulsation in a 4 GHz RF bandwidth and the red trace is the average power (c). This device tunes from 1220 to 1360 nm. The spectrogram (d) of the blue power trace (c), shows the pulsation frequency and the beat between adjacent pulses. The “U-shape” in the pulse repetition rate (d) is primarily due to variation in the MEMS filter linewidth across the tuning range.
Fig. 4
Fig. 4 Diagram of the simulated laser along with dots to color code the waveforms in Fig. 5.
Fig. 5
Fig. 5 Simulations for red- (a) and blue-tuning (b) swept sources (see Table 1). The wide light-green band in the instantaneous frequency plots marked “GHz” are the full-width half-maximum MEMS filter passbands. The green horizontal lines indicate the extent the light field “hops” in one round trip of the cavity.
Fig. 6
Fig. 6 The three steps for nonlinear blue tuning in a short, linear cavity laser.
Fig. 7
Fig. 7 Coherence length calculations using the procedure and laser model of Ref. [9] for blue- and red-tuning lasers of designs from Table 1. The simulated blue- and red-tuning coherence lengths are 23 and 15 mm respectively, approximately a 50% advantage for blue over red.
Fig. 8
Fig. 8 Experimental coherence revival point spreads for the blue-tuning laser are broadened because of the large dispersion from the semiconductor spacers inside the cavity used to make the laser more compact. The cavity round trip length changes by 0.75 mm over the tuning range. The bottom plots (b,d,f) show the chirp of the signal. The blue-inked curves (c,e) show the signal with the chirp removed. The calculated coherence curve in Fig. 9 has been corrected by the ratio of the red- to blue-inked peaks.
Fig. 9
Fig. 9 Theoretical and experimental coherence length and coherence revival data. The model is dispersionless, so the blue curve had to be adjusted to the green using dispersion data from Fig. 8. The calculation and experiment use a 20 mm depth antialiasing filter. The cavity length is 39 mm. The coherence length is 23 mm.
Fig. 10
Fig. 10 Experimental interference spectrogram showing main signal and artifacts from coherence revival [9,18,19].

Tables (2)

Tables Icon

Table 1 Blue-tuning laser simulation parameters along with hypothetical parameters of a red-tuning laser that is simulated for comparison.

Tables Icon

Table 2 Experimental laser parameters

Equations (2)

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

Δ n = α λ 4 π Δ g
Δ ν = L λ d n d t