传导冷却端面泵浦板条放大器波前畸变数值研究

 利用数值模拟的方法分析了均匀冷却与非均匀冷却对传导冷却端面泵浦板条放大器波前畸变的影响，结果发现：信号光的波前畸变强烈依赖于zig-zag周期数，一定的光路可以将波前畸变减小到λ/10量级；板条长度方向散热不均匀及两块热沉之间散热能力的差异对波前畸变的影响很小，而宽度方向散热不均匀对波前畸变的影响较大；当宽度方向散热不均匀时，波前畸变主要为倾斜像差，输出光束的传输方向将发生偏折。因此，在非均匀冷却条件下，为了减小宽度方向散热不均匀性的影响，应选择反射次数较少的之字型光路。

Thermal distortion analysis for conduction cooled end-pumped slab

The thermal distortion in the conduction cooled end-pumped zig-zag slab under different cooling conditions were analyzed by numerical simulation.The results indicate that the thermal distortion could be reduced by 3 orders of magnitude in zig-zag propagation.The inversion phenomenon of wave front was observed when different zig-zag optical paths were selected.The zig-zag optical path can eliminate the influence of the non-uniform heat dissipating capacity in length and height directions,but not in width direction.When the heat dissipating capacity in slab's width direction is non-uniform,the thermal distortion increases significantly and the propagation direction will be deviated.Therefore,when the heat dissipating capacity of the slab is non-uniform,small bounce number of zig-zag propagation is preferable to reduce the thermal distortion.