与常规的自发拉曼散射相比，受激拉曼散射 (SRS) 经常使用两束光场 (泵浦光和Stokes光)，这为偏振操控SRS过程提供了一个额外的自由度。为此，开展了泵浦光分别为圆偏振和线偏振的SRS对比研究。首先，基于非线性耦合波方程，从理论上分别推导了泵浦光为圆偏振和线偏振时 (Stokes光始终保持线偏振) SRS信号强度表达式。随后，以具有球对称的甲烷分子为例，实验测量了上述两种偏振光泵浦下甲烷分子υ₁和υ₃振动模在2800~3100 cm^-1的SRS光谱。实验结果与理论分析一致表明：SRS的信号强度不仅与泵浦光的偏振态有关，还与待测分子振动模式的对称性紧密相关。本研究结果为SRS的偏振应用提供了有益启示。

Compared with conventional spontaneous Raman scattering, stimulated Raman scattering (SRS) often uses two light fields (pump light and Stokes light), which provides an additional degree of freedom for polarization manipulation of SRS processes. A comparative study of SRS with circularly polarized and linearly polarized pump light field is carried out in this work. Firstly, based on the nonlinear coupled wave equation, the expressions of SRS signal intensity are derived theoretically under the cases that the pump light is circularly polarized and linearly polarized while Stokes light always keeps linearly polarized. And then, taking methane molecule with spherically symmetry as an example, the SRS spectra of υ₁ and υ₃ vibrational modes of methane molecule in the C-H stretching region (2800-3100 cm^-1) are experimentally measured under different polarizations. The experimental results are consistent with the theoretical analysis, demonstrating that the SRS signal intensity is not only closely related to the polarization state of pump light, but also to the symmetry property of molecular vibrational modes. The research provides useful insights for the polarization application of SRS.