受激旋转拉曼散射对强紫外激光相位的影响

Effect of stimulated rotational Raman scattering on phase of high-power ultraviolet laser beam

利用瞬态受激旋转拉曼散射(SRRS)模型及相位畸变模型,对具有空间相位畸变的强紫外激光束在空气中长程传输的SRRS效应进行了研究。详细讨论了低频和中高频空间相位畸变对SRRS阈值条件、斯托克斯光转换效率、剩余泵浦光和斯托克斯光相位的影响。研究结果表明,泵浦光的初始相位畸变对斯托克斯光相位畸变的影响较剩余泵浦光的更为明显;高频相位畸变对转换效率影响较低频相位畸变更大;SRRS效应阈值随低频相位畸变的增大而减小,随高频相位畸变的增大而增大。

Using the model of transient stimulated rotational Raman scattering （SRRS） and phase perturbation, SRRS effects on high power ultraviolet laser beams with phase noise through long air paths were studied. The effects of both low and high frequency phase perturbation on the threshold of the SRRS effects, the conversion efficiency of Stokes field and the phase of the residual pump field and the Stokes field were discussed in detail. The results show that the influence of the phase noise of the initial pump field on the Stokes field is more obvious than on the residual pump field. The variation of the conversion efficiency with the high frequency phase perturbation is larger than that with the low one. The SRRS threshold decreases with the increasing of the RMS value of low-frequency phase perturbation, and increases with the increasing of the modulation depth of the high frequency perturbation.