We report the measurement of the absolute
nonlinear coefficient of silver gallium sulfide from three phase-matched nonlinear interactions spanning from 10.2 to 0.78 µm: the sum-frequency of a laser (10.2 µm) and a near-IR AlGaAs diode laser (0.842 µm), the second-harmonic generation of a KCl:Li color-center laser (2.53 µm), and the noncritically phase-matched difference frequency between the AlGaAs diode laser and the KCl:Li laser to generate 1.265 µm. From the theoretical evaluation of the Gaussian-beam aperture functions for these type I interactions with arbitrary focusing parameters, beam-waist locations, and absorption losses, we have deduced from the three processes the same consistent value
for Our value is independent of the growth origin of the material. In light of the trustworthy value of measured from our experiments we analyze the feasibility of a continuous-wave doubly resonant parametric oscillator-(DRO-)based 3:1 frequency divider pumped by a near-IR diode laser. The predicted pump power threshold for the ring-resonator DRO lies in the range of 70–140 mW for a 14–18-mm-long sample with an absorption loss near the level of at the output frequencies.
© 1997 Optical Society of America