高功率半导体激光器端面泵浦Nd:YVO_4固体激光器热致损耗的研究

本文提出了一种测量端面泵浦固体激光器热致损耗的方法．研究了Ｎｄ（３＋）浓度分别为０．５％和２％两种Ｎｄ：ＹＶＯ４晶体，基模半径与泵浦光斑半径之比Ｗ１／Ｗｐ分别为０．５和１情形下热致损耗随泵浦功率的变化，结果表明：热致损耗随泵浦功率的增加而增大，且强烈依赖于Ｗ１／ＷＰ；大的基模半径会导致严重的热致损耗．Ｎｄ：ＹＶＯ４晶体的Ｎｄ３＋浓度对热致损耗也有很大影响，在大模半径情形，高浓度晶体的热致损耗远大于低浓度晶体，而且对于Ｗ１／Ｗｐ的依赖更为强烈．

Investigation of Thermally Indnced Losses in High-power Laser-diode-array End-pumped Nd:YVO_4 Solid-state Lasers

In this paper, a method for measuring thermally induced losses in highpower end-pumped solid-state lasers has been proposed. Using this method, we have investigated the variation of thermally induced losses with pump power, for two different Nd3 --doped YVO4 crystals (0.5%, and 2%), and with the ratio of mode radius to pump radius (W1/Wp) taking on the value of about 0.5 and 1, respectively. The results show that thermally induced losses increase with the rising of the pump power, and strongly depend on W1/Wp; large mode sizes lead to significantly high thermal losses. The results also reveal that the Nd3 concentration of Nd:YVO4 crystal has important influence on thermally induced losses; in the situation of large mode sizes, the thermal losses associated with heavily-doped crystals are much higher than those of lightly-doped crystals, and the dependence on W1/Wp is much stronger.