Measurements of the nonlinear refractive index of AgGaSe2, GaSe, and ZnSe at 10 µm

Abstract

We measure the four-wave mixing efficiency of dual-frequency, 300 ns, 10 µm C O 2 laser pulses to determine the effective nonlinear refractive index of the quadratic nonlinear crystals GaSe, A g G a S e 2 , and ZnSe relative to GaAs. The effective nonlinear refractive index of GaSe and A g G a S e 2 does not depend on the phase-matching conditions for second-harmonic and sum-frequency generation. This suggests that these measurements are representative of the intrinsic Kerr index and usable for infrared applications.