Optical Properties of Cd1-xMnxTe Epitaxial Films Deposited on Sapphire Substrates

Cd1-x Mn x Te epitaxial thin films with a smooth surface and high crystal quality were prepared on sapphire substrates by vacuum evaporation, and their Faraday effect and optical properties were investigated. The peak-to-peak rotation in the Verdet constant spectrum is 1.5 deg/Oe cm near the 0.57 µm wavelength at the energy gap for films where x=0.5. The refractive index at a 0.63 µm wavelength is 2.8∼3.0 for the x=0∼0.68 composition range, and it decreases as the Mn content increases. The optical attenuation at 1.52 µm decreases as the crystal quality improves, and the minimum attenuation is 2 dB/cm. Films with different structures have different attenuations. The wavelength dependence of the attenuation obeys Rayleigh's law of scattering. It is thought from these results that the attenuation is due to scattering based on the structure of the films.