对应用于惯性约束聚变(ICF)激光驱动器的新型N41大口径钕玻璃片在高增益条件下的热效应进行了系统研究。实验结果表明，在平均小信号净增益系数达到0.0525 cm-1的高增益情况下，385 mm×385 mm口径范围内两片双程的热致动态波前畸变的峰-谷值约为0.84λ(λ=1053 nm)，处于变形镜校正范围之内；基于目前的冷却方案，剩余波前畸变的恢复时间约为2.5 h，满足系统每4 h发射一次的设计要求；每次发射7 h后，系统内仍存在热气体对流引入的微小畸变；理论预测结果与实验结果一致。该研究为下一代ICF激光驱动器内片状放大器系统的研制提供了实验参考。

The thermal effect of a new large aperture N41 Nd∶glass slab which is applied to inertial confinement fusion (ICF) laser drivers is investigated systematically under the condition of high gain. The experimental results show that the peak-valley value of thermal induced wavefront distortion of two slabs with two pass within the diameter range of 385 mm×385 mm is about 0.84λ (λ=1053 nm) when the average small signal net gain coefficient reaches 0.0525 cm-1, which is in the revise extension of deformable mirror. Following the present cooling schemes, the recovery time of residual wavefront distortion is about 2.5 h, which is satisfied the designed requirement of launching once every 4 h. A minuteness wavefront distortion induced by thermal gas convention exists in the system after launching 7 h. Experimental results are consistent with numerical calculation results. The study provides an experimental reference for the design of the next generation slab amplification system in ICF laser drivers.