Phase-matching measurements for 10-microns upconversion in AgGaS2

Laboratory data from the upconversion of CO2 laser radiation using an AgGaS2 crystal pumped with a tunable dye laser are reported. Data were taken on the pump wavelength and bandwidth and the crystal acceptance angle for phase-matching. The results were compared with predictions made in terms of the upconversion conservation of energy and momentum and a model of the AgGaS2 refractive index. The trials were run with an annealed crystal apparently free of cracks, twins and optical scattering centers. The measurements indicated that more accurate refractrive-index data are required to be able to predict accurately the laser pump wavelength for phase-matching.