Nonlinear optical waveguides made of thin films of glass doped with semiconductor microcrystallites

Abstract

The rf sputtering technique was used to deposit thin films of CdS microcrystallite-doped glass onto standard glass substrates. The presence of the microcrystallites in the films was verified by using Raman spectroscopy. A sharp cutoff below 500 nm was visible on the transmission spectra of the semiconductor microcrystallite-doped films. The evidence of size effects was visible on both Raman and transmission spectra of the films. Power-dependent prism coupling of light into the waveguides was investigated under cw-illumination conditions. The angular variation in decoupled power becomes more asymmetric with increasing input power until switching occurs on one side of the characteristic. The nonlinearity involved is presumably of thermal origin.