液态介质纵向振动对受激布里渊散射反射性能的影响

结合静态流体力学理论、弦振动理论及瞬态受激布里渊散射(SBS)理论,建立了描述介质纵向振动所产生的附加密度变化的受激布里渊散射耦合模型。以四氯化碳为介质,研究了不同强度的基频及倍频振动对受激布里渊散射反射率以及波形失真度的影响特征。结果表明,振动对于受激布里渊散射的影响具有一定的阈值性。在低于某一阈值情况下,受激布里渊散射稳定性不受其影响,且受激布里渊散射的振动稳定性在很大程度上受控于受激布里渊散射装置的结构参数。在介质振动强度恒定的情况下,选取短焦透镜及短池长的装置结构更有利于受激布里渊散射相位共轭镜稳定性的提高。

Influence of Longitudinal Vibrating of Media on Stimulated Brillouin Scattering

Stimulated Brillouin scattering (SBS) can be utilized in laser systems to improve alignment stability.The stability of SBS is a key factor of limiting the system stability.Combining with the theory of hydrodynamics, vibrating string and transient SBS,a new SBS model with longitudinal vibrating of media is established.The eigenvalue of vibrating is obtained by solving the model.Basing on the model,the influence of longitudinal eigenvibrating and harmonic vibrating of tetrachloride with different intensities on the Stokes beams is investigated theoretically.The result shows that the influence of vibration on SBS has a certain threshold.When the intensity of vibration is less than some value,the stability of SBS is not affected.Another numerical simulation is carried out to research the dependence of stability on the configuration of SBS.It shows that the stability is enhanced when choosing lenses with shorter focus and shorter media cell.