Spontaneous-Raman-Scattering Efficiency and Stimulated Scattering in Silicon
Spontaneous-Raman-Scattering Efficiency and Stimulated Scattering in Silicon
复制标题
硅中的自发拉曼散射效率和受激散射
DOI：
10.1103/physrevb.2.1858
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发表时间：
1970
影响因子：
3.7
通讯作者：
R. Chang
中科院分区：
文献类型：
--
作者：
J. Ralston;R. Chang
使用工作频率为 1.064 μm 的连续激光器（钇铝石榴石中的 Nd）在 77 K 下测量了硅 521-cm−1 光学模式的绝对自发拉曼散射效率和线宽。测量的散射效率（沿晶体[111]方向的非偏振前向散射为 5.1×10−6/cm sr）和窄线宽产生受激拉曼增益系数的计算值，该值比其他介质（固体和液体）报告的值大得多。使用聚焦多模 Q 开关 YAG: Nd 激光器还可以在 77 K 下观察到 Si 中的受激拉曼散射。测量的受激增益的不准确性主要是由于硅内部有效焦体积的不确定性造成的。已经考虑了入射激光频率下的多光子吸收，并发现它可以显着地修改测量的受激增益。发现受激拉曼效应的估计增益与根据绝对自发拉曼散射效率计算出的增益非常一致。
The absolute spontaneous-Raman-scattering efficiency and linewidth of the 521-cm− 1 optical mode of silicon have been measured at 77 K using a continuous laser (Nd in yttrium aluminum garnet) operating at 1.064 μm. The measured scattering efficiency (5.1× 10− 6/cm sr for unpolarized forward scattering along the crystal [111] direction) and narrow linewidth yield a calculated value of the stimulated Raman gain coefficient which is considerably larger than those reported for other media, both solid and liquid. Stimulated Raman scattering in Si at 77 K has also been observed using a focused multimode Q-switched YAG: Nd laser. Inaccuracy in the measured stimulated gain resulted mainly from the uncertainty in the effective focal volume inside the silicon. Multiphoton absorption at the incident laser frequency has been considered and found to modify the measured stimulated gain by a significant amount. The estimated gain from the stimulated Raman effect was found to be in satisfactory agreement with that calculated from the absolute spontaneous-Raman-scattering efficiency.