DEGENERATE 4-WAVE-MIXING GEOMETRY IN THIN-FILM WAVE-GUIDES FOR NONLINEAR MATERIAL CHARACTERIZATION

We demonstrate experimentally a new degenerate four-wave mixing (DFWM) geometry in waveguides that permits the simultaneous determination of the nonlinear refractive index, the absorption, and the response time of the thin-film materials. The geometry consists of two guided pumps in a planar waveguide with an unguided probe. We achieve nonlinear ch aracterization by measuring only the DFWM signal and the guided pump p ower at the waveguide output. The technique has been tested on a polym eric film (di-alkylamino-nitro-stilbene). (C) 1996 Optical Society of America