Effect of crystal axis in temperature dependence of laser-induced damage thresholds by nanosecond near-infrared laser

Abstract

Laser-induced damage thresholds in crystalline quartz were evaluated using a single-mode Nd:YAG laser (wavelength 1064nm, pulse width 4ns) at temperatures ranging from 123K to 473K. In this experiment, three kinds of crystalline quartz different in the cut direction were prepared. The damage morphologies were coincident with the crystal structure. The laser induced damage thresholds in crystalline quartz differed according to the cutting direction. The laser-induced damage thresholds expect in the case of Z-cut sample increased with decreasing temperature. The cutting direction of the Z-cut of crystalline quartz was parallel to the crystal axis. A tendency of the temperature dependence was the same with in the case of the glass materials. In contrast, the laser-induced damage threshold of the Z-cut sample decreased with decreasing temperature. The difference in the temperature-dependent behaviors of crystalline quartz is explained using physical models. The crystal axis influenced strongly to the electron resistivity and the electron avalanche process in laser-induced damage mechanisms was affected in the result.