大口径N31钕玻璃片高增益情况下热性能研究

Investigation on Thermal Effect of N31 Neodymium Glass in High Gain Performance

大口径高通量验证实验平台(以下简称ITB装置)是我国为开展惯性约束聚变(ICF)研究而研制的激光装置,单束输出能量达到了19.6 k J(基频发射波长为1053 nm,脉宽为5 ns)。对大口径N31钕玻璃片在ITB装置400 mm×400 mm单口径片状放大器系统上应用的热特性进行了实验研究,结果表明:在增益系数为5.28%cm^(-1)高增益情况下,整个激光链路热致动态波前畸变峰谷值dPV约为5.3λ,处于变形镜校正范围之内;结合合理设计冷却方案,剩余波前畸变恢复时间约为2.5 h,满足了系统运行发次间隔为4 h的设计要求。

The integration-test-bed （ITB） device is established for research on inertial confinement fusion（ICF） in China. The single-beam output energy reaches 19.6 kJ successfully when the fundamental frequency emission wavelength is 1053 nm and the pulsewidth is 5 ns. Experimental results of thermal effect of 400 mm × 400 mm aperture slab amplifiers in ITB devices show that the peak-to-valley value dPV of pump-induced wave-distortion of the whole laser chain is about 5.3 l, in the revise extension of deformable mirror, when the gain coefficient is 5.28% cm-1. Combined with the optimizations of heat management, the thermal recovery time is about 2.5 h, which can satisfy the requirement of 4 h/shot.