Stimulated Raman scattering (SRS) is an effective technique for imaging, spectroscopy and for frequency conversion of lasers in all states of matter. Yet, controlling SRS frequency conversion efficacy is a great challenge, due to ensuing competing scattering processes and laser-induced thermal lensing (TL). Here, we focus on both SRS and the associated processes occurring during frequency conversion in an aqueous solution of sodium nitrate. It is demonstrated that SRS efficiently converts 532 nm nanosecond laser pulses, via a single pass through the solution. In this light-matter interaction, SRS along with four-wave mixing (FWM) converted the pump beam to collinear beams of the 1^st [yellow (564 nm)] and 2^nd [orange (599 nm)] Stokes of the NO₃⁻ ion symmetric stretch. The experimental results were well reproduced by a newly developed numerical model. Based on the experimental and numerical results, it was found that the 1^st Stokes is generated through SRS of the pump laser, while the onset and growth of the 2^nd Stokes were obtained through FWM. The results also reveal the significant role played by SRS induced TL, growing over many laser pulses, suggesting its substantial contribution and importance.

受激拉曼散射（SRS）是一种有效的技术，可用于在所有物质状态下进行成像，光谱学和激光频率转换。然而，由于随之而来的竞争性散射过程和激光感应热透镜（TL），控制SRS频率转换效率仍然是一个巨大的挑战。在这里，我们专注于SRS和硝酸钠水溶液在变频过程中发生的相关过程。事实证明，SRS通过单次通过溶液即可有效转换532 nm纳秒激光脉冲。在这种光-物质相互作用中，SRS与四波混频（FWM）一起将泵浦光束转换为NO _3的^第一个[黄色（564 nm）]和^第二个[橙色（599 nm）]斯托克斯的共线光束。^-离子对称拉伸。通过新开发的数值模型可以很好地再现实验结果。基于实验和数值结果，人们发现，在1^日斯托克斯通过泵激光的SRS生成的，而2个的开始和生长^ND是通过FWM得到斯托克斯。结果还表明，SRS诱导的TL在许多激光脉冲上均起着重要作用，表明其实质性贡献和重要性。