Nanosecond sum-frequency generating optical parametric oscillator using simultaneous phase matching

Abstract

Abstract:We report a nanosecond sum-frequency generating optical parametric oscillator based on a single KTiOAsO 4 crystal that is simultaneously phase matched for optical parametric generation and sum-frequency generation. Pumped at a wavelength of 1064 nm by a Q-switched Nd:YAG laser, this device produces 10.4-ns-long 8.3 mJ red pulses at a wavelength of 627 nm with 21% energy conversion efficiency. This device provides a simple and efficient method for converting high energy Nd:YAG lasers to a red wavelength.

Highly Efficient Wavelength Conversion of Q-Switched Nd:YAG Lasers Into a Red Wavelength

“…However, experimentally we determined that simultaneous phase matching at our wavelengths occurs at and , requiring a corresponding tilt. This propagation angle is quite close to the simultaneous phase-matching angle reported in [26] that was experimentally determined for a different KTA crystal and the angle calculated using the Sellmeier coefficients given in [27] for parametric generation and those given in [28] for SFG. The walk-off angles associated with the beams polarized along the fast axis are relatively small, with the maximum value being 0.15 for the sum-frequency beam, whereas the beams polarized along the slow axis experience no walk-off.…”

“…Digital Object Identifier 10.1109/JQE.2006.876711 Combining two steps of frequency conversion within the same nonlinear crystal using simultaneous phase matching facilitates efficient frequency conversion to wavelengths that cannot be reached via a single nonlinear process [17]- [26]. In particular, both femtosecond and cw Ti:sapphire laser beams have been upconverted to visible wavelengths by combining sum-frequency generation (SFG) [20], [21] or second-harmonic generation [21], [23], [24] with optical parametric oscillation.…”

“…In particular, both femtosecond and cw Ti:sapphire laser beams have been upconverted to visible wavelengths by combining sum-frequency generation (SFG) [20], [21] or second-harmonic generation [21], [23], [24] with optical parametric oscillation. We recently reported a sum-frequency generating OPO (SF-OPO) that extends this approach to the nanosecond regime [26].…”

Yellow nanosecond sum-frequency generating optical parametric oscillator using periodically poled LiNbO3

“…Another potentially efficient method for the generation of yellow light is by employing sum-frequency generation to an optical parametric oscillator (OPO). Recently a nanosecond sum-frequency generating optical parametric oscillator was reported using a single KTA crystal to generate red light at 627 nm [5] and a continuous wave device operating at 629 nm has also been reported based on PPLN [6]. Multistep parametric processes have been known for many years and simultaneous sum-frequency generation in an optical parametric oscillator was first demonstrated by Andrews et al [7].…”

Fourier transformed picosecond synchronously pumped optical parametric oscillator without spectral filtering element

“…Operation of tunable infrared OPO systems has previously been achieved using KTiOAsO 4 [6], KTiOPO 4 [7,8], BiB 3 O 6 [9], LiB 3 O 5 [10,11], KTiOAsO 4 [12] crystals. However, the spatial walk-off and reduced gain associated with the noncollinear interaction, limits the efficiency of the parametric process.…”