MEASUREMENT OF CLAMPED ELECTROOPTICAL COEFFICIENTS IN CDS, CDSE, AND CDS-CDSE

Polarimeter measurements of the electrooptical response of cadmium sul phide, cadmium selenide, and of the alloy cadmium sulphide-cadmium sel enide are performed at audio frequencies. The measured value of the r( c)(t) Pockels coefficient of CdSe, which is reported for the first tim e, is larger than that of CdS, as expected from the S-Se substitution. The electrooptical response of the CdS-CdSe alloy is smaller than tha t of both parent compounds, possibly due to the microscopic strains in the solid solution. A weak dependence of the electrooptical retardati on on the amplitude of the applied electric field is observed, and int erpreted as a Kerr contribution superimposed on the stronger Pockels e ffect.