We examined the physical properties of infrared optical glasses composed of tellurium, germanium, selenium, sulfur and silicon. In particular, we measured optical, acoustic and photoelastic parameters of the following alloy compounds: germanium–selenium–tellurium (Ge–Se–Te), germanium–selenium–sulfur–tellurium (Ge–Se–S–Te), germanium–silicon–tellurium (Ge–Si–Te) and silicon–tellurium (Si–Te). Like single-crystal tellurium, the glasses demonstrate good acousto-optic (AO) diffraction efficiency and have reasonable optical transparency in a wide spectral region covering wavelengths from 1.5 to 20 μm. The optical, acoustic and photoelastic properties of the tellurium-based compounds were measured using infrared lamp sources of radiation as well as He–Ne and CO2 lasers. In this paper, we report on the optical, acoustic and photoelastic parameters of a selection of these compounds and discuss the advantages and disadvantages of using these glasses for AO device applications. We also present the measured characteristics of an AO cell fabricated in a Si20Te80 glass material which exhibited high optical uniformity and long-term chemical stability.

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We examined the acoustical, optical and acousto-optical properties amorphous alloys based on germanium, selenium, silicium and tellurium. The phase velocities of longitudinal acoustic waves and the value of acousto-optic figure of merit of the tellurium-based compounds were measured using the infrared sources of light radiation on the wavelength λ = 3.39 μm. We measured the acousto-optic figure of merit of germanium single crystal in case of diffraction on the acoustic modes along [110] and [111].

We examined the optic, acoustic, photoelastic and acousto-optic (AO) properties of single crystal tellurium. We also determined the Bragg angle dependences on the acoustic frequency at 10.6 μm. The phenomenon of optical activity and its influence on the Bragg matching condition during anisotropic diffraction near the optic axis of the crystal are discussed in detail. Based on the results of our calculations, we designed, fabricated and characterized an AO cell to determine parameters of the anisotropic interaction with longitudinal acoustic waves propagating along the X axis in the crystal. In our experiments, we also measured the value of one of the important photoelastic coefficient in tellurium, p 41 =0.14±0.01 and demonstrated that this coefficient determines the efficiency of the anisotropic diffraction in the employed geometry.

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