High-efficiency 20–50 kHz mid-infrared orientation-patterned GaAs optical parametric oscillator pumped by a 2 μm holmium laser

Abstract

We report on what are, to our knowledge, the best results obtained with an orientation-patterned GaAs optical parametric oscillator (OPO) pumped by a Q-switched 2 microm Ho:YAG laser. Up to 2.85 W are obtained for 6.1 W of pump power, corresponding to an optical-to-optical conversion efficiency of 46.5% with a threshold of 1 W. Optical damage occurred at a fluence of about 2 J/cm2. The thickness of the crystal limited the pump power. Slope efficiencies are of the same order as those obtained with ZnGeP2 OPOs pumped with the same Ho:YAG laser.

Developments of mid-infrared optical parametric oscillators for spectroscopic sensing: a review

“…53 Now, people obtained high efficiency OPO with an orientation-patterned (OP) GaAs with tuning range covering from 2 to 9 μm. 59,60 A major constraint of OPGaAs-based OPO is the strong two-photon absorption, which limits the pump of OPGaAs with wavelengths longer than ∼1.8 μm.…”

Mid-Infrared Lasers

“…1 shows a recently measured tuning curve, demonstrating that a tunable Cr:ZnSe laser pumping an orientation-patterned GaAs (OP-GaAs) OPO can provide continuous tuning from 3 to 14 m using a single laser/OPO source [58]. In addition to continued improvement in QPM device growth processes and material quality [59], [60], QPM GaAs was shown to exhibit polarization-diverse frequency mixing [61] and has been demonstrated in a 20-50-kHz PRF OPO pumped by a Ho:YAG laser [62]. Demonstrated output was 2.85 W with 46% conversion efficiency.…”

High repetition rate, Q-switched Ho:YAG laser resonantly pumped by a 20 W linearly polarized Tm: fiber laser

“…Hybrid holmium laser systems would constitute a unique and irreplaceable source for further works carried out within laser technology. Moreover, tuneable 2-lm lasers can be suitable pump sources for optical parametric oscillators based on ZnGeP 2 (ZGP), GaAs crystals, which also constitute a novelty in the area of lasers operating at longer wavelengths (3-12 lm) [32,33].…”