Abstract

We report on the first demonstration of ZGP OPO based on Rotated Image Singly-Resonant Twisted RectAngle (RISTRA) cavity. For the OPO signal wave we achieved a near diffraction-limited beam at 3.4 μm with pulse energy of 10 mJ at repetition rate up to 500 Hz. As a pump source for the ZGP OPO, we utilized a 2-μm, TEM00, Ho:YLF MOPA system producing > 55 mJ energy per pulse at repetition rate range from single shot to 500 Hz.

© 2007 Optical Society of America

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  1. P. A. Budni, L. A. Pomeranz, M. L. Lemons, C. A. Miller, J. R. Mosto, and E. P. Chicklis, ‘‘Efficient mid-infrared laser using 1.9-μm-pumped Ho:YAG and ZnGeP2 optical parametric oscillator," J. Opt. Soc. Am. B 17, 723-728 (2000).
    [CrossRef]
  2. K. L. Vodopyanov, F. Ganikhanov, J. P. Maffetone, I. Zwieback, and W. Ruderman, "ZnGeP2 optical parametric oscillator with 3.8-12.4-μm tunability," Opt. Lett. 25, 841-843 (2000).
    [CrossRef]
  3. V. G. Dmitriev, G. G. Gurzadyan, and D. N. Nikogosyan, Handbook of Nonlinear Optical Crystals (Springer-Verlag, 1997).
  4. P. A. Budni, C. R. Ibach, S. D. Setzler, L. A. Pomeranz, M. L. Lemons, P. A. Ketteridge, E. J. Gustafson, Y. E. Young, P. G. Schunemann, T. M. Pollak, R. T. Castro, and E. P. Chiklis, "20-mJ, 3-5 micron ZnGeP2 optical parametric oscillator pumped by a 2.09-micron Ho:YAG laser," in Advanced Solid State Photonics, Technical Digest (Optical Society of America, 2003), paper PD12-1.
  5. E. Lippert, S. Nicolas, G. Arisholm, K. Stenersen, and G. Rustad, "Midinfrared laser source with high power and beam quality," Appl. Opt. 45, 3839-3845 (2006).
    [CrossRef] [PubMed]
  6. D. Gapontsev, N. Platonov, M. Meleshkevich, A. Drozhzhin, V. Sergeev, "415 W Single-Mode CW Thulium fiber laser in all-fiber format," in CLEO-Europe 2007, Technical Digest, paper CP2-3-THU.
  7. P. A. Budni, C. R. Ibach, S. D. Setzler, E. J. Gustafson, R. T. Castro, and E. P. Chicklis, "50-mJ, Q-switched, 2.09-μm holmium laser resonantly pumped by a diode-pumped 1.9-μm thulium laser," Opt. Lett. 28, 1016-1018 (2003).
    [CrossRef] [PubMed]
  8. M. Petros, J. Yu, U. N. Singh, and N. P. Barnes, "High energy directly pumped Ho:YLF laser," in Advanced Solid State Lasers, OSA Trends in Optics and Photonics Vol. 34, (Optical Society of America, 2000), pp. 178-181.
  9. A. Dergachev and P. F. Moulton, "High-power, high-energy diode-pumped Tm:YLF-Ho:YLF-ZGP laser system", in Advanced Solid-State Photonics, OSA Trends in Optic and Photonics Vol. 83, (Optical Society of America, 2003), pp. 137-141.
  10. A. Dergachev, P. F. Moulton, and T. E. Drake, "High-power, high-energy Ho:YLF laser pumped with Tm:fiber laser," in Advanced Solid-State Photonics, OSA Trends in Optic and Photonics Vol. 98, (Optical Society of America, 2005), pp. 608-612.
  11. A. V. Smith and D. J. Armstrong, "Nanosecond optical parametric oscillator with 90° image rotation: design and performance," J. Opt. Soc. Am. B 19, 1801-1814 (2002).
    [CrossRef]
  12. D. J. Armstrong and A. V. Smith, "90% pump depletion and good beam quality in a pulse-injection-seeded nanosecond optical parametric oscillator," Opt. Lett. 31, 380-382 (2006).
    [CrossRef] [PubMed]
  13. D. J. Armstrong and A. V. Smith, "All solid-state high-efficiency tunable UV source for airborne or satellite-based ozone DIAL systems," IEEE J. Sel. Top. Quantum Electron. 13, 721-731 (2007).
    [CrossRef]
  14. D. J. Armstrong and A. V. Smith, "150-mJ 1550-nm KTA OPO with good beam quality and high efficiency," Proc. SPIE 5337, 71-80 (2004).
    [CrossRef]
  15. D. J. Armstrong and A. V. Smith, "Using a Newport refractive beam shaper to generate high-quality flat-top spatial profiles from a flashlamp-pumped commercial Nd:YAG laser," Proc. SPIE 5525, 88-97 (2004).
    [CrossRef]
  16. http://www.sandia.gov/imrl/XWEB1128/xxtal.htm A complete package of numerical models for crystal nonlinear optics is available in the SNLO software package from A. V. Smith at Sandia National Labs. Models for the RISTRA OPO are available on request.
  17. 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]
  18. G. Anstett, M. Nittman, 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]
  19. A. V. Smith and D. J. Armstrong, "Generation of vortex beams by an image-rotating optical parametric oscillator," Opt. Express 11, 868-873 (2003).
    [CrossRef] [PubMed]

2007

D. J. Armstrong and A. V. Smith, "All solid-state high-efficiency tunable UV source for airborne or satellite-based ozone DIAL systems," IEEE J. Sel. Top. Quantum Electron. 13, 721-731 (2007).
[CrossRef]

2006

2004

G. Anstett, M. Nittman, 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]

D. J. Armstrong and A. V. Smith, "150-mJ 1550-nm KTA OPO with good beam quality and high efficiency," Proc. SPIE 5337, 71-80 (2004).
[CrossRef]

D. J. Armstrong and A. V. Smith, "Using a Newport refractive beam shaper to generate high-quality flat-top spatial profiles from a flashlamp-pumped commercial Nd:YAG laser," Proc. SPIE 5525, 88-97 (2004).
[CrossRef]

2003

2002

2000

1995

Appl. Opt.

Appl. Phys. B

G. Anstett, M. Nittman, 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]

IEEE J. Sel. Top. Quantum Electron.

D. J. Armstrong and A. V. Smith, "All solid-state high-efficiency tunable UV source for airborne or satellite-based ozone DIAL systems," IEEE J. Sel. Top. Quantum Electron. 13, 721-731 (2007).
[CrossRef]

J. Opt. Soc. Am. B

Opt. Express

Opt. Lett.

Proc. SPIE

D. J. Armstrong and A. V. Smith, "150-mJ 1550-nm KTA OPO with good beam quality and high efficiency," Proc. SPIE 5337, 71-80 (2004).
[CrossRef]

D. J. Armstrong and A. V. Smith, "Using a Newport refractive beam shaper to generate high-quality flat-top spatial profiles from a flashlamp-pumped commercial Nd:YAG laser," Proc. SPIE 5525, 88-97 (2004).
[CrossRef]

Other

http://www.sandia.gov/imrl/XWEB1128/xxtal.htm A complete package of numerical models for crystal nonlinear optics is available in the SNLO software package from A. V. Smith at Sandia National Labs. Models for the RISTRA OPO are available on request.

D. Gapontsev, N. Platonov, M. Meleshkevich, A. Drozhzhin, V. Sergeev, "415 W Single-Mode CW Thulium fiber laser in all-fiber format," in CLEO-Europe 2007, Technical Digest, paper CP2-3-THU.

M. Petros, J. Yu, U. N. Singh, and N. P. Barnes, "High energy directly pumped Ho:YLF laser," in Advanced Solid State Lasers, OSA Trends in Optics and Photonics Vol. 34, (Optical Society of America, 2000), pp. 178-181.

A. Dergachev and P. F. Moulton, "High-power, high-energy diode-pumped Tm:YLF-Ho:YLF-ZGP laser system", in Advanced Solid-State Photonics, OSA Trends in Optic and Photonics Vol. 83, (Optical Society of America, 2003), pp. 137-141.

A. Dergachev, P. F. Moulton, and T. E. Drake, "High-power, high-energy Ho:YLF laser pumped with Tm:fiber laser," in Advanced Solid-State Photonics, OSA Trends in Optic and Photonics Vol. 98, (Optical Society of America, 2005), pp. 608-612.

V. G. Dmitriev, G. G. Gurzadyan, and D. N. Nikogosyan, Handbook of Nonlinear Optical Crystals (Springer-Verlag, 1997).

P. A. Budni, C. R. Ibach, S. D. Setzler, L. A. Pomeranz, M. L. Lemons, P. A. Ketteridge, E. J. Gustafson, Y. E. Young, P. G. Schunemann, T. M. Pollak, R. T. Castro, and E. P. Chiklis, "20-mJ, 3-5 micron ZnGeP2 optical parametric oscillator pumped by a 2.09-micron Ho:YAG laser," in Advanced Solid State Photonics, Technical Digest (Optical Society of America, 2003), paper PD12-1.

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Figures (8)

Fig. 1.
Fig. 1.

Schematic layout of the end-pumped Ho:YLF MOPA (PBS – polarizing beam splitter, DM – Dichroic Mirror, AOM – Acousto-Optic Modulator, OC – Output Coupler, HR – High Reflector).

Fig. 2.
Fig. 2.

(a). Energy per pulse and pulsewidth for Ho:YLF master oscillator vs. pump power (TEM00 operation). (b) Oscillator beam profile at 500 Hz.

Fig. 3.
Fig. 3.

Block-diagram of Ho-MOPA system and the table detailing the pertinent parameters for each stage.

Fig. 4.
Fig. 4.

(a). Geometric configuration of the RISTRA OPO cavity. The two long legs can hold crystals with apertures up to 10×10 mm2 and length ≤ 17 mm and the two short legs contain λ/2-retardation plates to orient cavity polarizations parallel to the eigen-polarizations of the crystals. The ratio of the physical lengths of the cavity legs is √2. The angle of incidence on all cavity mirrors is 32.765°, and the nominal physical length of the cavity is 109 mm. In this figure the cavity contains one crystal and one λ/2-plate. For a two-crystal cavity the waveplate in the short horizontal leg must have retardation of λ/2 for the pump and resonated wave, and a second λ/2-plate is added to the short vertical leg. For our experiments the length of the ZGP crystal is 10 mm and the signal wavelength is 3.4 μm. The output coupler reflectivity is ~50%. (b) Exploded solid rendering of a two-crystal RISTRA cavity assembly showing cylindrical body, spring-loaded three-point mirror retainers and mirror substrates, waveplate holders, and crystal rotation assemblies. Owing to its non-planar geometry the RISTRA requires no cavity mirror adjustments. The length of the cylinder is 50 mm, and the mirror substrates have diameters of 12.5 mm and thickness of 3 mm. See text for additional details.

Fig. 5.
Fig. 5.

(a). Depleted and undepleted pump pulse temporal profiles showing ~35% pump depletion for 3.4-μm signal energy of ~10 mJ. Percent pump depletion, defined as 100×(Aundep-Adep)/Aundep, where Aundep and Adep are time-integrated areas for the undepleted and depleted pump pulses, provides a measure of total conversion efficiency. Measurements were obtained from a detector with 1-ns resolution that monitored pump energy after the pump beam passed through the cavity. The undepleted pump pulse was recorded by blocking circulation of the signal inside the OPO cavity. (b) Contour plot of the spatial fluence profile of the 3.4-μm signal beam in the far field plotted against the far-field angles θ and θ where ∥ and ⊥ denote directions parallel and perpendicular to birefringent walk-off in the ZGP crystal. The far-field fluence was recorded with a 500-mm focal length lens with effective f/# ≈ 140. Approximating the diffraction-limited focal-spot diameter by λf/# suggests a far-field angular spread of <0.8 mrad, indicating the signal beam quality exceeds the diffraction limit by at most a factor of 1.8. A rigorous M2 analysis using second moments from two-dimensional spatial fluence profiles would yield a more accurate value for this factor. Spatial integration of the fluence profile indicates that approximately 14% of the total energy of ~10 mJ falls within the diffraction limited sport size, or within ± 0.4 mrad in the far field. (c) Surface plot of (b).

Fig. 6.
Fig. 6.

Measured and calculated efficiency curves showing OPO signal energy at 3.4 μm versus 2.05-μm pump energy. The calculated curve was obtained from a two-dimensional model for the RISTRA OPO that assumes a single-frequency pump laser and single-frequency oscillation in the OPO, and includes biregringent walk-off, diffraction, and image rotation. Measured performance is for a broadband pump laser with a free running OPO. With the broadband pump and oscillation, the signal linewidth was measured to be slightly less than 40 nm near 3.4 μm. The difference in the oscillation thresholds can be partially attributed to start-up from quantum fluctuations in the signal and idler fields for the laboratory measurements, opposed to start-up using an injection seeding source in the model. Additional discrepancies can be attributed to uncertainty in the value of effective nonlinearity, d eff, used for ZGP in the calculations, and to the various physical mechanisms described in the text. For these calculated and measured results, the length of the ZGP crystal is 10 mm and the pump 1/e2-diameter 4.0–4.5 mm. The output coupler reflectivity is ~50%.

Fig. 7.
Fig. 7.

Measured average power of the RISTRA OPO 3.4-um signal wave and 2-um pump vs the repetition rate. Pump pulse energy was set at 50 mJ for each repetition rate. The average power of the OPO signal wave does increase linearly with the increasing repetition rate. This shows that OPO performance is not affected by the thermal effects at pump average power of up to 25 W.

Fig. 8.
Fig. 8.

(a). Far field signal spatial fluence profile for a one-crystal KTP RISTRA OPO where the Nd:YAG pump laser and OPO are each injection-seeded for single-frequency oscillation. The mixing in xz-cut KTP is 0.532(o) → 0.800(e) + 1.588(o). The pump beam diameter was ~5 mm and its spatial fluence profile was globally flat-topped but contained ring-like modulation due to hard apertures from overfilled laser amplifier rods. The OPO’s injection-seeded oscillation threshold was 23 mJ and the pump energy was 4× the threshold. In contrast to the mid-IR system, the cavity Fresnel number for the KTP RISTRA is approximately 200, and the diffraction-limited focal-spot diameter and corresponding far-field angular spread are respectively 100 μm and 200 μrad. Approximately 24% of the total 0.800-μm signal energy falls within ± 0.1 mrad. (b) Far field signal fluence for the same experimental conditions as in (a) except the pump laser and OPO are now unseeded for broadband oscillation. The small reduction in peak height in the far field is real, and is accompanied by a reduction in conversion efficiency when compared to single-frequency oscillation. Now approximately only 13% of the total signal energy falls within ±0.1 mrad, consistent with the results for broadband oscillation in Fig. 5.

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