Abstract

Complicated spectrotemporal processes are associated with the generation of signal and idler output pulses on a nanosecond timescale in an injection-seeded optical parametric oscillator (OPO). The mechanisms of such spectrotemporal dynamics are revealed by numerical simulation, including innovative modeling of instantaneous-frequency profiles and frequency chirp. These simulations are in satisfactory agreement with optical-heterodyne measurements of output from a nanosecond-pulsed OPO system that is based on periodically poled KTiOPO4, pumped at 532nm by a Nd:YAG laser and injection-seeded at a signal wavelength of 842nm. Frequency chirp in narrowband signal output pulses from such an OPO system has previously been observed to depend on phase mismatch between the pump, signal, and idler waves, and also on the pump-pulse energy. Our simulations accurately predict this behavior and yield realistic estimates of the frequency chirp, optical bandwidth, and spectral purity of the signal output pulse as it evolves, including effects that are not readily observed directly. This approach provides insight into instrumental conditions that facilitate continuously tunable, single-longitudinal-mode operation of such a pulsed OPO system, with optical bandwidth as close as possible to the Fourier-transform limit.

© 2007 Optical Society of America

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  1. R. T. White, Y. He, B. J. Orr, M. Kono, and K. G. H. Baldwin, "Pulsed injection-seeded optical parametric oscillator with low frequency chirp for high-resolution spectroscopy," Opt. Lett. 28, 1248-1250 (2003).
    [CrossRef] [PubMed]
  2. R. T. White, Y. He, B. J. Orr, M. Kono, and K. G. H. Baldwin, "Control of frequency chirp in nanosecond-pulsed laser spectroscopy. 1. Optical-heterodyne chirp analysis techniques," J. Opt. Soc. Am. B 21, 1577-1585 (2004).
    [CrossRef]
  3. R. T. White, Y. He, B. J. Orr, M. Kono, and K. G. H. Baldwin, "Control of frequency chirp in nanosecond-pulsed laser spectroscopy. 2. A long-pulse optical parametric oscillator for narrow optical bandwidth," J. Opt. Soc. Am. B 21, 1586-1594 (2004).
    [CrossRef]
  4. R. T. White, Y. He, B. J. Orr, M. Kono, and K. G. H. Baldwin, "Transition from single-mode to multimode operation of an injection-seeded pulsed optical parametric oscillator," Opt. Express 12, 5655-5660 (2004).
    [CrossRef] [PubMed]
  5. G. Arisholm, G. Rustad, and K. Stenersen, "Importance of pump-beam group velocity for backconversion in optical parametric oscillators," J. Opt. Soc. Am. B 18, 1882-1890 (2001).
    [CrossRef]
  6. G. Anstett, A. Borsutzky, and R. Wallenstein, "Investigation of the spatial beam quality of pulsed ns-OPOs," Appl. Phys. B 76, 541-545 (2003).
    [CrossRef]
  7. G. Anstett, M. Nitmann, and R. Wallenstein, "Experimental investigation and numerical simulation of the spatio-temporal dynamics of the light pulses in nanosecond optical parametric oscillators," Appl. Phys. B 79, 305-313 (2004).
    [CrossRef]
  8. G. Anstett and R. Wallenstein, "Experimental investigation of the spectro-temporal dynamics of the light pulses of Q-switched Nd:YAG lasers and nanosecond optical parametric oscillators," Appl. Phys. B 79, 827-836 (2004).
    [CrossRef]
  9. A. V. Smith, "Bandwidth and group-velocity effects in nanosecond optical parametric amplifiers and oscillators," J. Opt. Soc. Am. B 22, 1953-1965 (2005).
    [CrossRef]
  10. M. Kono, K. G. H. Baldwin, R. T. White, Y. He, and B. J. Orr, "Heterodyne-assisted pulsed spectroscopy with a nearly Fourier-transform limited, injection-seeded optical parametric oscillator," Opt. Lett. 30, 3413-3415 (2005).
    [CrossRef]
  11. M. Kono, K. G. H. Baldwin, R. T. White, Y. He, and B. J. Orr, "CHAPS: a new precision laser-spectroscopic technique," J. Opt. Soc. Am. B 23, 1181-1189 (2006).
    [CrossRef]
  12. R. T. White, "Quasi-phase-matched nonlinear-optical devices," Ph.D. dissertation (Macquarie University, Sydney, 2004).
  13. F. J. Harris, "On the use of windows for harmonic analysis with the discrete Fourier transform," Proc. IEEE 66, 51-83 (1978).
    [CrossRef]
  14. S. Gangopadhyay, N. Melikechi, and E. E. Eyler, "Optical phase perturbations in nanosecond pulsed amplification and second-harmonic generation," J. Opt. Soc. Am. B 11, 231-241 (1994).
  15. N. Melikechi, S. Gangopadhyay, and E. E. Eyler, "Phase dynamics in nanosecond pulsed dye laser amplification," J. Opt. Soc. Am. B 11, 2402-2411 (1994).
    [CrossRef]
  16. S. Gangopadhyay, "Optical phase distortions in nanosecond laser pulses and their effects on high resolution spectroscopy," Ph.D. dissertation (University of Delaware, 1995).
  17. A. V. Smith, SNLO, public-domain software (Sandia National Laboratories). It is available as a free download at http://www.sandia.gov/imrl/X1118/xxtal.htm.
  18. A. V. Smith, R. J. Gehr, and M. S. Bowers, "Numerical models of broad-bandwidth nanosecond optical parametric oscillators," J. Opt. Soc. Am. B 16, 609-619 (1999).
    [CrossRef]
  19. E. S. Cassedy and M. Jain, "A theoretical study of injection tuning of optical parametric oscillators," IEEE J. Quantum Electron. QE-15, 1290-1301 (1979).
    [CrossRef]
  20. K. Kato and E. Takaoka, "Sellmeier and thermo-optic dispersion formulas for KTP," Appl. Opt. 41, 5040-5044 (2002).
    [CrossRef] [PubMed]
  21. T. D. Raymond, W. J. Alford, A. V. Smith, and M. S. Bowers, "Frequency shifts in injection-seeded optical parametric oscillators with phase mismatch," Opt. Lett. 19, 1520-1522 (1994).
    [CrossRef] [PubMed]
  22. A. V. Smith, W. J. Alford, T. D. Raymond, and M. S. Bowers, "Comparison of a numerical model with measured performance of a seeded, nanosecond KTP optical parametric oscillator," J. Opt. Soc. Am. B 12, 2253-2267 (1995).
    [CrossRef]
  23. S. E. Harris, "Tunable optical parametric oscillators," Proc. IEEE 57, 2096-2113 (1969).
    [CrossRef]
  24. J. E. Bjorkholm, "Some effects of spatially nonuniform pumping in pulsed optical parametric oscillators," IEEE J. Quantum Electron. QE-7, 109-118 (1971).
    [CrossRef]
  25. R. A. Baumgartner and R. L. Byer, "Optical parametric amplification," IEEE J. Quantum Electron. QE-15, 432-444 (1979).
    [CrossRef]
  26. Y. X. Fan, R. C. Eckardt, R. L. Byer, J. Nolting, and R. Wallenstein, "Visible BaB2O4 optical parametric oscillator pumped by a single-axial-mode pulsed source," Appl. Phys. Lett. 53, 2014-2016 (1988).
    [CrossRef]
  27. M. J. Johnson, "Development of pulsed, tunable, optical parametric oscillators for spectroscopic applications," Ph.D. dissertation (Macquarie University, 1995).
  28. G. W. Baxter, J. G. Haub, and B. J. Orr, "Backconversion in a pulsed optical parametric oscillator: evidence from injection-seeded sidebands," J. Opt. Soc. Am. B 14, 2723-2730 (1997).
    [CrossRef]

2006 (1)

2005 (2)

2004 (5)

2003 (2)

2002 (1)

2001 (1)

1999 (1)

1997 (1)

1995 (1)

1994 (3)

1988 (1)

Y. X. Fan, R. C. Eckardt, R. L. Byer, J. Nolting, and R. Wallenstein, "Visible BaB2O4 optical parametric oscillator pumped by a single-axial-mode pulsed source," Appl. Phys. Lett. 53, 2014-2016 (1988).
[CrossRef]

1979 (2)

R. A. Baumgartner and R. L. Byer, "Optical parametric amplification," IEEE J. Quantum Electron. QE-15, 432-444 (1979).
[CrossRef]

E. S. Cassedy and M. Jain, "A theoretical study of injection tuning of optical parametric oscillators," IEEE J. Quantum Electron. QE-15, 1290-1301 (1979).
[CrossRef]

1978 (1)

F. J. Harris, "On the use of windows for harmonic analysis with the discrete Fourier transform," Proc. IEEE 66, 51-83 (1978).
[CrossRef]

1971 (1)

J. E. Bjorkholm, "Some effects of spatially nonuniform pumping in pulsed optical parametric oscillators," IEEE J. Quantum Electron. QE-7, 109-118 (1971).
[CrossRef]

1969 (1)

S. E. Harris, "Tunable optical parametric oscillators," Proc. IEEE 57, 2096-2113 (1969).
[CrossRef]

Alford, W. J.

Anstett, G.

G. Anstett, M. Nitmann, and R. Wallenstein, "Experimental investigation and numerical simulation of the spatio-temporal dynamics of the light pulses in nanosecond optical parametric oscillators," Appl. Phys. B 79, 305-313 (2004).
[CrossRef]

G. Anstett and R. Wallenstein, "Experimental investigation of the spectro-temporal dynamics of the light pulses of Q-switched Nd:YAG lasers and nanosecond optical parametric oscillators," Appl. Phys. B 79, 827-836 (2004).
[CrossRef]

G. Anstett, A. Borsutzky, and R. Wallenstein, "Investigation of the spatial beam quality of pulsed ns-OPOs," Appl. Phys. B 76, 541-545 (2003).
[CrossRef]

Arisholm, G.

Baldwin, K. G. H.

Baumgartner, R. A.

R. A. Baumgartner and R. L. Byer, "Optical parametric amplification," IEEE J. Quantum Electron. QE-15, 432-444 (1979).
[CrossRef]

Baxter, G. W.

Bjorkholm, J. E.

J. E. Bjorkholm, "Some effects of spatially nonuniform pumping in pulsed optical parametric oscillators," IEEE J. Quantum Electron. QE-7, 109-118 (1971).
[CrossRef]

Borsutzky, A.

G. Anstett, A. Borsutzky, and R. Wallenstein, "Investigation of the spatial beam quality of pulsed ns-OPOs," Appl. Phys. B 76, 541-545 (2003).
[CrossRef]

Bowers, M. S.

Byer, R. L.

Y. X. Fan, R. C. Eckardt, R. L. Byer, J. Nolting, and R. Wallenstein, "Visible BaB2O4 optical parametric oscillator pumped by a single-axial-mode pulsed source," Appl. Phys. Lett. 53, 2014-2016 (1988).
[CrossRef]

R. A. Baumgartner and R. L. Byer, "Optical parametric amplification," IEEE J. Quantum Electron. QE-15, 432-444 (1979).
[CrossRef]

Cassedy, E. S.

E. S. Cassedy and M. Jain, "A theoretical study of injection tuning of optical parametric oscillators," IEEE J. Quantum Electron. QE-15, 1290-1301 (1979).
[CrossRef]

Eckardt, R. C.

Y. X. Fan, R. C. Eckardt, R. L. Byer, J. Nolting, and R. Wallenstein, "Visible BaB2O4 optical parametric oscillator pumped by a single-axial-mode pulsed source," Appl. Phys. Lett. 53, 2014-2016 (1988).
[CrossRef]

Eyler, E. E.

Fan, Y. X.

Y. X. Fan, R. C. Eckardt, R. L. Byer, J. Nolting, and R. Wallenstein, "Visible BaB2O4 optical parametric oscillator pumped by a single-axial-mode pulsed source," Appl. Phys. Lett. 53, 2014-2016 (1988).
[CrossRef]

Gangopadhyay, S.

Gehr, R. J.

Harris, F. J.

F. J. Harris, "On the use of windows for harmonic analysis with the discrete Fourier transform," Proc. IEEE 66, 51-83 (1978).
[CrossRef]

Harris, S. E.

S. E. Harris, "Tunable optical parametric oscillators," Proc. IEEE 57, 2096-2113 (1969).
[CrossRef]

Haub, J. G.

He, Y.

Jain, M.

E. S. Cassedy and M. Jain, "A theoretical study of injection tuning of optical parametric oscillators," IEEE J. Quantum Electron. QE-15, 1290-1301 (1979).
[CrossRef]

Johnson, M. J.

M. J. Johnson, "Development of pulsed, tunable, optical parametric oscillators for spectroscopic applications," Ph.D. dissertation (Macquarie University, 1995).

Kato, K.

Kono, M.

Melikechi, N.

Nitmann, M.

G. Anstett, M. Nitmann, and R. Wallenstein, "Experimental investigation and numerical simulation of the spatio-temporal dynamics of the light pulses in nanosecond optical parametric oscillators," Appl. Phys. B 79, 305-313 (2004).
[CrossRef]

Nolting, J.

Y. X. Fan, R. C. Eckardt, R. L. Byer, J. Nolting, and R. Wallenstein, "Visible BaB2O4 optical parametric oscillator pumped by a single-axial-mode pulsed source," Appl. Phys. Lett. 53, 2014-2016 (1988).
[CrossRef]

Orr, B. J.

M. Kono, K. G. H. Baldwin, R. T. White, Y. He, and B. J. Orr, "CHAPS: a new precision laser-spectroscopic technique," J. Opt. Soc. Am. B 23, 1181-1189 (2006).
[CrossRef]

M. Kono, K. G. H. Baldwin, R. T. White, Y. He, and B. J. Orr, "Heterodyne-assisted pulsed spectroscopy with a nearly Fourier-transform limited, injection-seeded optical parametric oscillator," Opt. Lett. 30, 3413-3415 (2005).
[CrossRef]

R. T. White, Y. He, B. J. Orr, M. Kono, and K. G. H. Baldwin, "Transition from single-mode to multimode operation of an injection-seeded pulsed optical parametric oscillator," Opt. Express 12, 5655-5660 (2004).
[CrossRef] [PubMed]

R. T. White, Y. He, B. J. Orr, M. Kono, and K. G. H. Baldwin, "Control of frequency chirp in nanosecond-pulsed laser spectroscopy. 1. Optical-heterodyne chirp analysis techniques," J. Opt. Soc. Am. B 21, 1577-1585 (2004).
[CrossRef]

R. T. White, Y. He, B. J. Orr, M. Kono, and K. G. H. Baldwin, "Control of frequency chirp in nanosecond-pulsed laser spectroscopy. 2. A long-pulse optical parametric oscillator for narrow optical bandwidth," J. Opt. Soc. Am. B 21, 1586-1594 (2004).
[CrossRef]

R. T. White, Y. He, B. J. Orr, M. Kono, and K. G. H. Baldwin, "Pulsed injection-seeded optical parametric oscillator with low frequency chirp for high-resolution spectroscopy," Opt. Lett. 28, 1248-1250 (2003).
[CrossRef] [PubMed]

G. W. Baxter, J. G. Haub, and B. J. Orr, "Backconversion in a pulsed optical parametric oscillator: evidence from injection-seeded sidebands," J. Opt. Soc. Am. B 14, 2723-2730 (1997).
[CrossRef]

Raymond, T. D.

Rustad, G.

Smith, A. V.

Stenersen, K.

Takaoka, E.

Wallenstein, R.

G. Anstett, M. Nitmann, and R. Wallenstein, "Experimental investigation and numerical simulation of the spatio-temporal dynamics of the light pulses in nanosecond optical parametric oscillators," Appl. Phys. B 79, 305-313 (2004).
[CrossRef]

G. Anstett and R. Wallenstein, "Experimental investigation of the spectro-temporal dynamics of the light pulses of Q-switched Nd:YAG lasers and nanosecond optical parametric oscillators," Appl. Phys. B 79, 827-836 (2004).
[CrossRef]

G. Anstett, A. Borsutzky, and R. Wallenstein, "Investigation of the spatial beam quality of pulsed ns-OPOs," Appl. Phys. B 76, 541-545 (2003).
[CrossRef]

Y. X. Fan, R. C. Eckardt, R. L. Byer, J. Nolting, and R. Wallenstein, "Visible BaB2O4 optical parametric oscillator pumped by a single-axial-mode pulsed source," Appl. Phys. Lett. 53, 2014-2016 (1988).
[CrossRef]

White, R. T.

Appl. Opt. (1)

Appl. Phys. B (3)

G. Anstett, A. Borsutzky, and R. Wallenstein, "Investigation of the spatial beam quality of pulsed ns-OPOs," Appl. Phys. B 76, 541-545 (2003).
[CrossRef]

G. Anstett, M. Nitmann, and R. Wallenstein, "Experimental investigation and numerical simulation of the spatio-temporal dynamics of the light pulses in nanosecond optical parametric oscillators," Appl. Phys. B 79, 305-313 (2004).
[CrossRef]

G. Anstett and R. Wallenstein, "Experimental investigation of the spectro-temporal dynamics of the light pulses of Q-switched Nd:YAG lasers and nanosecond optical parametric oscillators," Appl. Phys. B 79, 827-836 (2004).
[CrossRef]

Appl. Phys. Lett. (1)

Y. X. Fan, R. C. Eckardt, R. L. Byer, J. Nolting, and R. Wallenstein, "Visible BaB2O4 optical parametric oscillator pumped by a single-axial-mode pulsed source," Appl. Phys. Lett. 53, 2014-2016 (1988).
[CrossRef]

IEEE J. Quantum Electron. (3)

J. E. Bjorkholm, "Some effects of spatially nonuniform pumping in pulsed optical parametric oscillators," IEEE J. Quantum Electron. QE-7, 109-118 (1971).
[CrossRef]

R. A. Baumgartner and R. L. Byer, "Optical parametric amplification," IEEE J. Quantum Electron. QE-15, 432-444 (1979).
[CrossRef]

E. S. Cassedy and M. Jain, "A theoretical study of injection tuning of optical parametric oscillators," IEEE J. Quantum Electron. QE-15, 1290-1301 (1979).
[CrossRef]

J. Opt. Soc. Am. B (10)

G. W. Baxter, J. G. Haub, and B. J. Orr, "Backconversion in a pulsed optical parametric oscillator: evidence from injection-seeded sidebands," J. Opt. Soc. Am. B 14, 2723-2730 (1997).
[CrossRef]

A. V. Smith, W. J. Alford, T. D. Raymond, and M. S. Bowers, "Comparison of a numerical model with measured performance of a seeded, nanosecond KTP optical parametric oscillator," J. Opt. Soc. Am. B 12, 2253-2267 (1995).
[CrossRef]

A. V. Smith, "Bandwidth and group-velocity effects in nanosecond optical parametric amplifiers and oscillators," J. Opt. Soc. Am. B 22, 1953-1965 (2005).
[CrossRef]

R. T. White, Y. He, B. J. Orr, M. Kono, and K. G. H. Baldwin, "Control of frequency chirp in nanosecond-pulsed laser spectroscopy. 1. Optical-heterodyne chirp analysis techniques," J. Opt. Soc. Am. B 21, 1577-1585 (2004).
[CrossRef]

R. T. White, Y. He, B. J. Orr, M. Kono, and K. G. H. Baldwin, "Control of frequency chirp in nanosecond-pulsed laser spectroscopy. 2. A long-pulse optical parametric oscillator for narrow optical bandwidth," J. Opt. Soc. Am. B 21, 1586-1594 (2004).
[CrossRef]

G. Arisholm, G. Rustad, and K. Stenersen, "Importance of pump-beam group velocity for backconversion in optical parametric oscillators," J. Opt. Soc. Am. B 18, 1882-1890 (2001).
[CrossRef]

S. Gangopadhyay, N. Melikechi, and E. E. Eyler, "Optical phase perturbations in nanosecond pulsed amplification and second-harmonic generation," J. Opt. Soc. Am. B 11, 231-241 (1994).

N. Melikechi, S. Gangopadhyay, and E. E. Eyler, "Phase dynamics in nanosecond pulsed dye laser amplification," J. Opt. Soc. Am. B 11, 2402-2411 (1994).
[CrossRef]

M. Kono, K. G. H. Baldwin, R. T. White, Y. He, and B. J. Orr, "CHAPS: a new precision laser-spectroscopic technique," J. Opt. Soc. Am. B 23, 1181-1189 (2006).
[CrossRef]

A. V. Smith, R. J. Gehr, and M. S. Bowers, "Numerical models of broad-bandwidth nanosecond optical parametric oscillators," J. Opt. Soc. Am. B 16, 609-619 (1999).
[CrossRef]

Opt. Express (1)

Opt. Lett. (3)

Proc. IEEE (2)

S. E. Harris, "Tunable optical parametric oscillators," Proc. IEEE 57, 2096-2113 (1969).
[CrossRef]

F. J. Harris, "On the use of windows for harmonic analysis with the discrete Fourier transform," Proc. IEEE 66, 51-83 (1978).
[CrossRef]

Other (4)

R. T. White, "Quasi-phase-matched nonlinear-optical devices," Ph.D. dissertation (Macquarie University, Sydney, 2004).

S. Gangopadhyay, "Optical phase distortions in nanosecond laser pulses and their effects on high resolution spectroscopy," Ph.D. dissertation (University of Delaware, 1995).

A. V. Smith, SNLO, public-domain software (Sandia National Laboratories). It is available as a free download at http://www.sandia.gov/imrl/X1118/xxtal.htm.

M. J. Johnson, "Development of pulsed, tunable, optical parametric oscillators for spectroscopic applications," Ph.D. dissertation (Macquarie University, 1995).

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Figures (7)

Fig. 1
Fig. 1

Computer screen dump of recently developed interactive software for chirp analysis, based on optical-heterodyne detection and a Fourier-transform algorithm. The software displays, in real time, the recorded beat waveform (top, left) and its Fourier transform (with filter function; top and center, right), the reconstructed OPO signal pulse profile (center, left), the calculated f inst ( t ) profile (bottom, left), and a summary of calculated pulse durations and chirp parameters (bottom right) for 50% and 10% intensity ranges. Vertical dashed lines in the left-hand panels designate the 10% intensity points. In this example, the OPO is well seeded and the frequency chirp is very low ( < 10 MHz ) .

Fig. 2
Fig. 2

Monochromatic plane-wave simulations, based on the SNLO PW-OPO-LP code [17], of signal output pulse energies as a function of pump pulse energy E p for a pulsed PPKTP OPO that is operated either unseeded and free running (solid curve) with λ free = 841.75 ± 0.01 nm or injection seeded (dashed curve) with λ s = 841.76 nm (i.e., effectively equal to λ free , to minimize frequency chirp). Corresponding observed signal output pulse energies [3] are also plotted (×=unseeded, free running; 엯=injection seeded). Vertical arrows designate the three values of pump pulse energy E p for which simulated temporal profiles are presented in Fig. 3.

Fig. 3
Fig. 3

SNLO PW-OPO-LP simulations [17] of PPKTP OPO temporal profiles (solid curves, unseeded, free running; dashed curves, injection seeded) for depleted pump pulses (left-hand column) and signal output pulses (right-hand column), at the three arrowed settings of E p in Fig. 2. Input pump pulse profiles are depicted by dotted–dashed curves in the left-hand column.

Fig. 4
Fig. 4

Top: broadband PW simulations, based on the SNLO PW-OPO-BB code [17], of signal output pulse energies as a function of pump pulse energy E p for a pulsed PPKTP OPO that is operated either unseeded and free running (solid curve) or injection seeded (dashed curve) with corresponding observed signal output pulse energies [3] (×=unseeded, free running; 엯=injection seeded) as in Fig. 2. Center: PW-OPO-BB simulation (solid curve) of the temporal profile for the signal output pulse from the unseeded PPKTP OPO with E p = 102 μ J and R p = 3.8 . The corresponding PW-OPO-LP simulation is shown for comparison (dotted-dashed curve). Bottom: corresponding PW-OPO-BB (solid curve) and PW-OPO-LP (dotted–dashed curve) simulations of the temporal profile for the depleted pump pulse from the unseeded PPKTP OPO. The PW-OPO-BB simulations provide a more realistic representation of the unseeded OPO because backconversion effects are more adequately treated by the PW-OPO-BB model than by the PW-OPO-LP model.

Fig. 5
Fig. 5

SNLO PW-OPO-LP simulations [17] of PPKTP OPO operation with R p = 2 , for a variety of detunings of seeded signal wavelength λ s from λ free and corresponding phase mismatches Δ k . The left-hand column shows measured (dashed curve) and simulated (solid curve) temporal profiles of the OPO signal output pulse, with λ s values annotated. The right-hand column shows experimental (dashed curves) and simulated (solid curves) profiles of the instantaneous frequency f inst ( t ) , with Δ k values annotated. These results confirm our previous observations [1, 3] that the frequency chirp is approximately proportional to Δ k and that it is minimized by setting Δ k = 0 .

Fig. 6
Fig. 6

SNLO PW-OPO-BB simulations [17] of signal output pulses from an injection-seeded PPKTP OPO as in previous experiments [4] with λ s = 841.78 nm and λ free = 841.94 nm , resulting in a large phase mismatch ( Δ k = 0.69 cm 1 ) that yields a transition from SLM to multimode operation as the times-above-threshold parameter R p increases over a range from R p = 1.6 [(a)–(c)] to R p = 3.5 [(m)–(o)]. The left-hand column [(a), (d), (g), (j), (m)] depicts simulated and measured temporal profiles, including rapid walk-off oscillations in the simulations. The central column [(b), (e), (h), (k), (n)] depicts simulated and experimental profiles of the instantaneous frequency f inst ( t ) . The right-hand column [(c), (f), (i), (l), (o)] depicts the optical bandwidth Δ ν (left-hand ordinate) and the spectral purity (right-hand ordinate), each simulated by the PW-OPO-BB model.

Fig. 7
Fig. 7

Top: PW-OPO-BB simulation of signal intensity for the OPO pulse output with R p = 3.5 and Δ k = 0.69 cm 1 as in Fig. 6m, indicating two 1 ns time intervals ( t 1 = 15 16 ns and t 2 = 28 29 ns ) that are used for Fourier transformation to generate the spectra shown in the lower panels. Center: normalized power-density spectrum (after Fourier transformation of the complex-valued signal amplitude) for time interval t 1 , yielding a narrow optical bandwidth Δ ν (above the 20 dB level) and a high spectral purity (SP). Bottom: corresponding spectrum for time interval t 2 , yielding a much broader optical bandwidth Δ ν ( 500 GHz above the 20 dB level) and a spectral purity of 30%, with a much less prominent central SLM peak. These spectra correlate with the results plotted in Fig. 6o.

Tables (1)

Tables Icon

Table 1 Adjustable Parameters Used as Input to the SNLO Model

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