Linear Electrooptic Properties of ZnTe at 10.6 Microns

The low-frequency linear electrooptic coefficientr41Tin semi-insulating ZnTe is measured at 10.6 µm at room temperature. The measured value is (3.9±0.2)×10-12m/V, which is only slightly smaller than that in the visible region. This result seems consistent with a lattice theory on the dispersion ofr41Tin crystals of a zincblende structure [D.P. Akittet al; IEEE J. Quantum Electronics QE-6 (1970) 496]. The induced birefringence in ZnTe at 10.6 µm is about 30 percent larger than that in GaAs, and about 35 percent smaller than that in CdTe. The figure of merit for the materialF1(that is inversely proportional to the electric power necessary for a lumped modulator) at 10.6 µm is found to be twice as large in ZnTe as in GaAs, which is the material most widely used for the electrooptic light modulation at 10.6 µm.