冷却中的不对称对N41型钕玻璃主放大片剩余温度场的影响

Effect of Asymmetry in Cooling on Residual Temperature Field of an N41-Type Neodymium Glass Main Amplifier Slab

钕玻璃激光放大片在热恢复后的剩余温度场对于光束退偏和波前畸变具有重要的影响。当冷却过程中出现不对称情形,将导致剩余温度场的不对称,从而影响到高功率激光光束发次之间的重复性。本文在对N41型钕玻璃四周包边侧弱冷和强冷所导致的剩余温度场分布特征进行模拟分析的基础上,重点研究了包边侧不对称冷却所导致的剩余温度场的变化。这种变化的程度与钕玻璃四周包边侧冷却的强弱有关,并进一步分析了由弱冷转为强冷时钕玻璃激光放大片的通光面和四周包边界面上各自的散热量。

The residual temperature field of a neodymium glass laser amplifier slab after thermal recovery significantly affects beam depolarization and wavefront distortion.When asymmetry occurs during the cooling process,it causes an asymmetrical distribution of the residual temperature field,which in turn affects the repeatability of the high-power laser beam between shots.This study conducted a simulation of the residual temperature field distribution characteristics derived from weak and strong cooling applied to the cladding sides of an N41-type neodymium glass slab.Changes to the residual temperature field caused by asymmetric cooling on the cladding sides were then investigated,where the degree of change is related to the strength of cooling on the cladding sides of the neodymium glass slab.Heat dissipation on the light-passing surfaces and cladding interfaces of the neodymium glass slab was further analyzed when weak cooling transformed to strong cooling.