1.9-W cw ring-cavity KTP singly resonant optical parametric oscillator

Experimental realization of broadband parametric generation in a quasi-periodically poled LiTaO3

We have achieved broadband parametric generation by using a quasi-periodically poled LiTaO(3) crystal as frequency converter. Tuning wavelength rang from 0.609 microm to 5.208 microm, which covered three quasi-phase-matching processes, was obtained by means of changing the pump wavelength from 0.530 microm to 1.184 microm. The experiment results are in good agreement with theory. The maximum conversion efficiency is 62% with a 10 Hz-5 ns pump source, at the average pump power of 0.5 mW. Our results exhibit a possible application of quasi-periodic superlattice in laser technology.

Continuous-wave singly resonant optical parametric oscillator placed inside a ring laser

A cw singly resonant optical parametric oscillator (SRO) was built and placed inside the cavity of a ring laser. The system consists of a diode-end-pumped Nd:YVO4 ring laser with intracavity periodically poled lithium niobate as the nonlinear gain medium of the SRO. When the laser was operated in a unidirectional mode, we obtained more than 520 mW of signal power in one beam. When the laser was operated in a bidirectional mode, we obtained 600 mW of signal power (300 mW in two separate beams). The power and the spectral features of the laser in the unidirectional and bidirectional modes were measured while the laser was coupled with the SRO. The results show that it is preferable to couple a SRO with a unidirectional ring laser.

Conoscopic interferometry of surface-acoustic-wave substrate crystals

Conoscopic interferometry is applied for determining the crystal orientation of lithium niobate and other commonly employed substrate wafers for integrated-optic and surface-acoustic-wave devices. The method is particularly applicable for detecting the orientation of the optic axes of the strongly birefringent niobate but is less sensitive for lithium tantalate or quartz. Conoscopic interference is a low-cost and easy-to-use method that is especially suitable for laboratory usage.

Continuous-wave 532-nm-pumped singly resonant optical parametric oscillator based on periodically poled lithium niobate

We report a continuous-wave (cw) 532-nm-pumped singly resonant optical parametric oscillator (SRO) based on periodically poled lithium niobate. The pump source is a commercial 5-W cw diode-pumped, multilongitudinal-mode, intracavity-doubled Nd:YVO(4) laser. Using a four-mirror ring SRO cavity and single-pass pumping, we achieved subwatt internal oscillation threshold, 56% quantum efficiency, and output tuning from 917 to 1266 nm.

Mode-volume and pump-power limitations in injection-locked TEM(00) Nd:YAG rod lasers

Stress-induced birefringence in cw-pumped Nd:YAG rods create stability limitations on the TEM(00) polarized mode of a resonant cavity. We present and verify experimentally a thermo-optical model describing a ring cavity containing a birefringent cw-pumped Nd:YAG rod. We use the model, along with experimental evidence, to show that a fundamental TEM(00) mode size and pump-power limitation exists for any cw-pumped Nd:YAG laser, implying a maximum allowable TEM(00) output. We show that the largest TEM(00) mode radius that can be supported in the rod is approximately 1.1 mm and is independent of the physical size of the rod.

Continuous-wave singly resonant pump-enhanced type II LiB(3)O(5) optical parametric oscillator

We report what is to our knowledge the first demonstration of a pump-enhanced singly resonant continuous-wave optical parametric oscillator. The nonlinear material used was lithium triborate cut for noncritical phase matching along the z axis, and the device was pumped by a single-frequency argon-ion laser. The oscillation threshold was ~1.0 W at 514.5 nm. For 3.4 W of pump power, we obtained single-frequency output powers of 500 mW in the nonresonant wave, which we temperature tuned over 14 nm.