Raman temperature measurement during photostructural changes in GexSe1−x glass

Direct measurement of sample temperature was performed during sub-bandgap photoinduced structural changes in bulk Ge–Se glasses. The temperature was determined by analysis of the Raman signal scattered from the microvolume of the sample undergoing photostructural change. The temperature measurement was done with 800 nm laser light at three different intensities. The sub-bandgap laser light induced photodarkening, photorelaxation, and photoexpansion in the glass samples but did not increase the temperature significantly. The temperature measurements of the irradiated microvolume represent a direct observation of the athermal nature of photoinduced structural changes in bulk Ge–Se glasses.