Birefringence in CdGa2S4 Crystals

Abstract

In СdGа2S4 crystals Fabry-Perot and birefringence interference spectra were investigated. Spectral dependences of refraction indexes for ordinary and extraordinary light waves are defined. The spectral dependence Δn = ne - no from the short and long-wavelength parts of isotropic wavelength is determined. It is established that at λ > λ0 Δn is positive and at λ < λ0 Δn is negative. Wavelength λ0 = 485.7 nm shifts with decreasing temperature to short-wavelengths. The band in reflection spectra observed at the isotropic wavelength has a small halfwidth (∽3 - 5 Å). Another isotropic wavelength was found in the shortwavelength region (433 nm) for crystals obtained by iodine transport method.