聚焦光束稳态热晕补偿实验

进行了聚焦光束稳态热晕效应及自适应光学补偿的室内模拟实验观测，获得了在不同热畸变参数情况下，自适应光学系统开闭环时光束远场Strehl比和信标光波前方差的测量结果。测量结果表明自适应光学对聚焦光束整束热晕的补偿效果是显著的。在热畸变参数Nd大于170时，校正剩余波前大差呈非线性增长。在热畸变参数N_d与光束菲涅耳数N_f的比值大于1时，校正后的远场光斑峰值强度随入射功率的增加开始呈下降趋势。

Compensation of Steady-static Thermal Blooming Induced by Focused Beam

Simulation experiment of adaptive optics compensation to thermal blooming phasedistortion induced by a focusing laser beam is done. The adaptive optics has 37 correctionelements. In the experiment, the beam Fresnel number is set 140. The. steady-staticresults are given both in Strehl ratio and residual wavefront variance for different distortionnumbers. It is seen that the residual wavefront variance linearly increase as the ratio ofdistortion number N_d to the beam Fresnel number N_f becomes large, but smaller than1. Also the experiment presents that the compensated far-field intensity goes down whenthe ratio of distortion number N_d to the beam Fresnel number N_f becomes greater than1. In this case, the compensated beam Strehl ratio goes down rapidly.