SPECTRA OF NATURAL AND PHOTOINDUCED LINEAR DICHROISM IN CHALCOGENIDE GLASSES

Spectra of natural and photoinduced linear dichroism in the range of 570 to 630 nm are investigated for the first time in some bulk chalcogenide glasses of various composition. In As34S52I14 and As2S3 glasses, the natural dichroism is shown to be positive, small and approximately constant in the whole spectral range studied. The dichroism induced by the sub-band-gap light beam is negative, large and has substantial spectral selectivity. The form of the dichroism spectrum changes during the inducing time, and the dichroism maximum shifts gradually to the shorter wavelengths range towards the wavelength of inducing light. In GeS2.2 glass, the form of dichroism is determined by the natural dichroism that changes value and sign in the spectral range studied. The results are discussed taking into consideration the interaction of linearly polarized light with the anisotropic defects distributed energetically in the gap of the glass.