Linear electrooptic effect in HgS (Cinnabar) at 0.63 and 3.39 microns

Nonlinear optical properties of HgS have been of interest lately. The electrooptic effect has been measured in a natural crystal and values for the two independent coefficients are reported here at wavelengths of 0.63 and 3.39 microns. The results agree well with predictions of purely electronic theories, but the wavelength dependence indicates an appreciable contribution of ionic motion to the optical polarizability.