An Ultrasonic Study of Some Optical Glasses

Abstract

Ultrasonic delay time in typical optical glasses was measured between -20° and 120°C using superposition method at 5 MHz, which assured the precision of 1 in 104. It was found out that the temperature coefficients of delay time of measured glasses lie in the range of ±50 ppm/°C, and shift from negative to positive as SiO2 content decreases. The frequency dependence of acoustic loss was also measured using pulse echo method up to 130 MHz, and was found to be in the range of 0.01∼0.03 dB per unit wavelength.