Dielectric and Optical Properties of KTaO3

Electrical field dependence of the dielectric constant in KTaO 3 has been measured under the bias field up to 15 kV/cm and in the temperature range between 300 K and 4.2 K. Characteristics of the induced polarization as functions of electric field and of temperature were obtained. A hysteresis phenomenon in the biasing cycle of the dielectric constant was observed at lower temperatures, the characteristics of which were analysed based on a layered structure model. Refractive index of the crystal has been measured in the wave-length region between 0.4 µ and 1.1 µ, and is analysed by the Sellmeier form. The relevance of these experimental results to the nonlinear optical experiment is briefly discussed.