CHI((3)) NONLINEAR SUSCEPTIBILITY IN II-VI COMPOUNDS AND APPLICATIONSFOR SQUEEZED-LIGHT GENERATION IN SEMICONDUCTORS

We have measured the nonlinear refractive index near half-bandgap (E(g )/2) in ZnS and ZnSe by self-phase modulation experiments. The ratio o f the nonlinear phase shift and the total optical absorption losses is critically dependent on the detuning from E(g)/2. Efficient quadratur e squeezing was obtained at a centre wavelength of 780 nm in ZnS and a t 960 nm in ZnSe. The scheme we employed can generally be applied to s emiconductors, and opens the way for squeezed light generation over a wide range of wavelengths.