2-PHOTON ABSORPTION AND NONLINEAR REFRACTION OF LANTHANUM SULFIDE-GALLIUM SULFIDE GLASSES

The two-photon absorption coefficient (beta) and nonlinear refractive index (gamma) of the binary La2S3-Ga2S3 and ternary MS-La2S3-Ga2S3 (MS =Ag2S and Na2S) glasses were measured at 532 nm by the Z-scan method. The beta of the glasses was similar to 40 cm GW(-1) and nearly unchang ed with La2S3 content in the binary glasses, while it increased, or de creased with the substitution of Ag2S, or Na2S, respectively, for La2S 3 in the ternary glasses. The gamma of the glasses increased, with the rising La2S3 content in the binary glasses, and increased, or decreas ed with the addition of Ag2S3 or Na2S, respectively, in the ternary gl asses. The results were compared with the third-order nonlinear optica l properties measured by third harmonic generation and discussed on th e basis of their linear optical properties. (C) 1998 American Institut e of Physics. [S0021-8979(98)05517-0].