Thermal Analysis of Rectangular Nd:YVO4 Crystal Double-Side-Pumped by LD

Abstract

Based on analytical theory, distributions of temperature field and thermal distortion field in a rectangular Nd:YVO4 crystal double-side-pumped by LD are investigated. Through the analysis of working characteristics of Nd:YVO4 crystal, a thermal model that matches actual situations of Nd:YVO4 crystal is established. General expressions of temperature field and thermal distortion field in Nd:YVO4 crystal are obtained. And two methods of effectively reducing thermal distortion in Nd:YVO4 crystal are put forward. Results show that a maximum temperature rise of 362.2°C and a maximum thermal distortion of 5.55 μm are obtained in Nd:YVO4 crystal when the output power of the two laser diodes used to pump the Nd:YVO4 crystal are both 30 W. When the off- center distance is 0.6mm, the maximum thermal distortion can be reduced by37.7%; when the thickness of the crystal is reduced by 30%, the maximum thermal distortion can be reduced by 31.7%. Results in this paper can offer theoretical base for better solving thermal problems in laser system.