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本文利用小起伏线性理论,给出了在非均匀吸收大气并伴有随机风速切变情况下高能激光大气传输的对数光强起伏和相位起伏以及Strehl比的普遍表达式。Strehl比的计算结果表明,由于存在小尺度热晕相位校正的不稳定性,和湍流效应相位补偿不同,只有适当地选择变形镜驱动器的间距,相位校正才有效。随机风速可以部分地抑制小尺度热晕不稳定性与相位校正不稳定性,从而提高了高能激光发射的临界能量密度。但在实际大气中,它的数值还要比产生整束热晕相位校正不稳定性的临界激光能量密度小一个量级以上。
In this paper, we give the general expression of logarithmic light intensity fluctuation and phase undulation and Strehl ratio in high-energy laser atmospheric transmission under non-uniform atmospheric absorption with random wind shear. The Strehl ratio results show that the phase correction is effective only with the proper spacing of the anamorphic mirrors due to the instability of the small-scale corona phase correction and the phase compensation of turbulence effects. Stochastic wind speed can partially suppress the small-scale thermal instability and phase-correction instability, thus increasing the critical energy density of high-energy laser emission. However, in the real atmosphere, its value is still more than one order of magnitude smaller than the critical laser energy density that produces the instability of phased beam coherence correction.