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

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 362.2degC and a maximum thermal distortion of 5.55 mum 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 0.6 mm, the maximum thermal distortion can be reduced by 37.7%; 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.