Measurements of the Linear Electrooptic Coefficients and Analysis of the Nonlinear Susceptibilities in Cubic GaAs and Hexagonal CdS

The unclamped values of the linear electrooptic coefficients r₄₁^T in GaAs and r₃₃^T, r₁₃^T, r_c^T and r₄₂^T in CdS have been measured at the wavelengths of 1.15, 3.39 and 10.6 µm as well as those of the coefficients r_c^T and r₄₂^T in CdS at 0.633 µm. The measured values are as follows: In GaAs r₄₁^T=1.43±0.07, 1.24±0.04, 1.51±0.05×10^-12 m/V at 1.15, 3.39 and 10.6 µm respectively. In CdS r₃₃^T=3.2±0.2, 2.9±0.1, 2.75±0.08×10^-12 m/V, r₁₃^T=3.1,±0.2, 3.5±0.1, 2.45±0.08×10^-12 m/V, r_c^T=6.2±0.2, 6.5±0.2, 5.2±0.3×10^-12 m/V, r₄₂^T=2.0±0.2, 2.0±0.2, 1.7±0.3×10^-12 m/V at 1.15, 3.39 and 10.6 µm respectively, and r_c^T=4.8±0.2×10^-12 m/V, r₄₂^T=1.6±0.2×10^-12 m/V at 0.633 µm. Using the measured data and data on nonlinear optical coefficients obtained by others, the anharmonic potential coefficients are determined and the dispersion of the unclamped linear electrooptic coefficients and nonlinear optical coefficients for SHG are calculated.