摘要
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。
The formulas of logarithm amplitude and phase fluctuation as well as the Strehl ratiofor high energy laser beam propagating in the nonuniform atmosphere including randomwind shear are given by using linearized theory. The results of the Strehl ratio showthat the small scale instability induced by the interaction between turbulence and thermalblooming and that the phase compensation instability(PCI) make phase compensationeffective only at actuator numbers chosen properly, which is different from the case of phasecompensation applied to correct beam distortion due to pure turbulence efiect. Resultsalso indicate the fact that random wind shear will partly depress the instability, making thecritical energy density high for laser beam transmitting possibly through the atmosphere.However, in the real atmosphere, this critical intensity is still lower in approximately oneorder than that of whole beam thermal blooming phase compensation instability.
出处
《量子电子学报》
CAS
CSCD
1998年第2期175-185,共11页
Chinese Journal of Quantum Electronics
基金
国家高技术发展计划激光领域资助
关键词
湍流
小尺度热晕
相位补偿
不稳定性
激光传输
turbulence, small scale thermal blooming, phase compensation, instability
