粗糙热传导表面下激光介质的热效应

在考虑激光介质与热沉不完全接触导热的情况下,用面热源自适应调整算法计算了激光介质的温度场,研究了其热效应.表面附近相位差存在起伏且深入一定深度使热效应复杂化.随抽运功率的增大,表面附近相位差的起伏增强,而起伏深度变化不明显;接触面积增大,相位差起伏减小,起伏的深度有所减小.抽运功率较小时,热致衍射损耗随抽运功率的增大近似线性增大,高斯光半径越大,增大的斜率越大,当抽运功率增加到一定程度时,热致衍射损耗增大的趋势减缓,半径大的减缓较明显.在抽运光功率变化范围内,半径大的高斯光热致衍射损耗大于半径小的.高斯光半径较小时,接触面积对热致衍射损耗的影响不明显,当高斯光半径较大时,接触面积减小热致衍射损耗增大.

Thermal Effect of Laser Medium with Rough Surface Heat Conduction

Taking account of the fact that the laser medium always cannot contact completely with the heat sink, the temperature of the laser medium is computed and its thermal effect is studied. Phase difference near the surface has a sizable fluctuation and therefore complicates the thermal effect. The fluctuation near the surface becomes greater with the increasing pump power, while the change of its depth is unconspicuous. The phase fluctuation as well as its depth reduces with the increasing contact area. At low pump power, the diffraction loss increases linearly with it, the larger the beam radius, the bigger the slope, when the pump power increases to some values, the slope becomes smaller, especially the beam with larger radius. Compared to the smaller radius beams, the larger radius beams has bigger losses for all powers. The variation of the diffraction loss with the contact area is not significant in small beam radius, while the diffraction loss increases with the contact area reduces in larger beam radius.