Photostimulated absorption of light in chalcogenide glass fibers

An investigation was made of photostimulated absorption of light in chalcogenide glass fibers when a side surface of a fiber was illuminated with unresolved (white) or monochromatic light. It was found that such additional illumination of fibers with low-intensity ~2×10^–6 W/cm²) monochromatic light of photon energy lower or higher than the optical band gap increased the absorption by the fiber material. The results were interpreted by charge exchange between localized states due to intrinsic or impurity defects.