GLASSES AND OPTICAL IR FIBERS OF As//2Se//3// minus //xTe//x.

Chalcogenide glasses of As//2Se//3// minus //xTe//x(0 less than multiplied by less than 3) were made. From these materials optical fibers were pulled, and the attenuation of CO//2 laser light (wavelength lambda equals 10. 6 mu m) transmitted through these fibers was measured as a function of the Te content (x). The fiber's surface and cross-section were examined. The influence of the physical and mechanical properties on the concentration of defects was studied by measuring the optical absorption ( alpha ) and the microhardness (V//H) of the raw materials. Slabs of As//2Se//3// minus //xTe//x were made, and in these samples the alpha , V//H, and glass transition temperature (T//g) as a function of x were measured. In the infrared region of the spectra at lambda equals 10. 6 mu m, the alpha in both the slabs and pulled fibers increased, and the V//H and T//g decreased with the increase of x. This can be explained by the increase of the concentration of the defects (small crystallites) which appeared during the fiber pulling.