Abstract

All-optical switches are generally designed to operate with intensity-dependent refractive index, which results from the third-order nonlinear susceptibility χ⁽³⁾. In this paper, the real part of χ⁽³⁾ observed at a signal wavelength λ_s is examined in CdS_xSe_1-x-doped glass pumped at λ_p ≠ λ_s. It is shown that, comparing to the case of being pumped at λ_s, which is longer than a band gap wave-length, larger Reχ⁽³⁾, typically by a factor of 10³, is obtained at λ_s when pumped at the wavelength close to the band edge. The large χ⁽³⁾ obtained at low absorption wavelength gives us flexibility in designing a variety of all-optical devices.

© 1994 IEEE