Opt Lett. 2013 Nov 15;38(22):4849-52. doi: 10.1364/OL.38.004849.
Free carrier absorption (FCA) in silicon is the major obstacle toward achieving optical gain in Si nanostructure systems. In this Letter, we present experimental results of pump-induced loss for TE and TM polarization in multislot SiO2/nc-Si waveguides. Continuous wavelength and ultrafast studies of carriers excited in the nc-Si multilayers reveal strong suppression of transmission loss related to FCA in Si nanostructures for TM-polarized probe light. We demonstrate theoretically and experimentally that FCA may be reduced under TM polarization as much as 9 times compared to TE polarization.
自由载流子吸收（FCA）是硅中实现光学增益的主要障碍。在这封信件中，我们给出了多狭缝 SiO2/nc-Si 波导中 TE 和 TM 偏振的泵浦诱导损耗的实验结果。对 nc-Si 多层中激发的载流子进行连续波长和超快研究表明，TM 偏振探针光的传输损耗与 Si 纳米结构中的 FCA 有很强的抑制作用。我们从理论和实验上证明，与 TE 偏振相比，TM 偏振可以将 FCA 降低多达 9 倍。
