Measurements of the electrooptic effect in CdS, ZnTe, and GaAs at 10.6 microns

Low-frequency electrooptic coefficients have been measured for three semiconductors at 10.5 microns. The results are
r_{c} = (5.5 \pm 1) \times 10^{-12}
m/V for CdS,
r_{41} = (1.4 \pm 0.2) \times 10^{-12}
m/V for ZnTe, and
r_{41} = (1.6 \pm 0.1) \times 10^{-12}
m/V for GaAs. A comparison is made of the efficiencies of these materials in different modulator configurations. The effect of photoelectrically induced space charge is discussed briefly.