荧光物质光学性质对受激拉曼散射的影响

Influence of Fluorescent Medium Optical Characteristics on Stimulated Raman Scattering

荧光在受激拉曼散射中能发挥良好的外部种子作用,可以极大幅度降低受激拉曼阈值、增加散射模式的强度。将溶解了荧光物质的CS2溶液作为液芯光纤的芯液体进行荧光增强受激拉曼散射研究。结果表明,很小能量(1.86 mJ)的激光激发就能获得较强的斯托克斯和反斯托克斯拉曼光。以荧光光谱范围较小的罗丹明B(rhodamine B)作为荧光种子,只获得了强度较高的一阶反斯托克斯谱线和强度较低的一阶斯托克斯谱线;以荧光光谱范围很大的β-胡萝卜素(β-carotene)作为荧光种子,很小的抽运能量就获得了7阶斯托克斯光谱。因此可以选用不同光学性质的荧光种子来选择性增强受激拉曼散射的某一散射模式。

The fluorescence is demonstrated a well out-seeding effect in the stimulated Raman scattering（SRS）,which can drastically lower the SRS threshold and enhance the intensity of scattering-mode.The solution of fluorescent seeding in CS2 is used to the study of the fluorescence enhancement SRS in liquid-core optical fiber（LCOF）.The results demonstrate that the stronger intensity of Stokes and anti-Stokes scattering light can be observed at low pump energy.The rhodamine B of narrow fluorescent spectrum is used,and the high intensity of first-order anti-Stokes line and low intensity of first-order Stokes line are obtained;and the β-carotene of broad fluorescent seeding is used,the seventh-order Stokes lines are obtained at low pump energy.So,the scattering mode of SRS can be selectively enhanced according to the different optical characteristics of fluorescent seeding.