Tunable laser sources in the mid-infrared (MIR) spectral range are required for several Air Force applications. Existing lasers with output in the near-infrared can be converted to more desirable MIR by using nonlinear effects. Orientation patterned gallium arsenide (OPGaAs) is a promising nonlinear conversion material because it has broad transparency and can be engineered for specific pump laser and output wavelengths using quasi-phase matching techniques. This research examines optical parametric oscillation (OPO) of several OPGaAs samples using a 2.052 micrometers wavelength Tm, Ho:YLF pump laser. Of the seven samples available the five that were capable of getting OPO output with this pump were tested and OPO was successfully demonstrated on 4 of the 5. The highest slope efficiency of 10% was seen in sample 5. The highest pump power of incident 190 mW without causing damage to the AR coatings was applied to sample 4. Finally spectroscopic data of input and output was obtained and compared to calculated values
