5C3 - GaAs as an electrooptic modulator at 10.6 microns

The electrooptic properties of a number of semiconductors were investigated. Of particular interest was the possibility of using these materials for modulation of infrared radiation, since many of the efficient modulation materials for the shorter wavelengths, such as KTN and KDP, are opaque in this region. We have investigated experimentally the modulation potential of a number of semiconducting materials. These include ZnS and GaAs of the noncentrosymmetric 43m class. The electrooptic coefficients were determined by using a Co
2
, 10.6μ and a He-Ne 3.39 μ laser as the radiation source. Based on our experiments, GaAs appears as a suitable material for infrared modulation at
\lambda > 10\mu
.