Study of picosecond optical switch controlled by optical light using graphene-loaded optical waveguides

本项目的目标是在光通信频段通过石墨烯加载光波导的有效控制来实现高速全光开关。所提出的开关是基于我们先前提出的拉曼放大控制的全光波长选择开关。石墨烯中的光饱和吸收可以用来控制光信号的幅度。首先，我们利用飞秒激光光源实验测量了石墨烯加载光波导中光功率依赖的插入损耗及其与光偏振的关系。测试结果表明，该开关的插入损耗变化可达10d B，可应用于该开关。其次，从理论上分析了可饱和吸收伴随折射率变化控制的光开关。我们发现，通过考虑伴随的折射率变化可以提高开关效率。

This project aims to realize a high-speed all-optical switch by efficient control with graphene-loaded waveguides in the optical communication band. The proposed switch is based on our previously proposed all-optical wavelength-selective switch controlled by Raman amplification. Optical saturable absorption in graphene can be used to control the optical signal amplitude. First, we experimentally measured optical power-dependent insertion-loss in a graphene-loaded waveguide and its dependence on optical polarization by using a femtosecond laser source. The measured result shows that the obtained 10-dB change of insertion loss can be enough large for applying to the proposed switch. Next, we theoretically analyzed optical switching controlled by saturable absorption accompanied by refractive-index change. We found that the switching efficiency can be improved by considering the accompanied refractive-index change.