基于高迁移率透明导电氧化物的高速、低插入损耗硅基光波导移相器研究

High-Speed and Low-Insertion-Loss Silicon Waveguide Phase Shifter Based on High Mobility Transparent Conductive Oxides

硅基光波导移相器是硅基光电子系统的重要组成部分。透明导电氧化物(TCO)薄膜的介电常数受栅极电压作用会产生调谐,有望应用于下一代高速、低插入损耗且兼容CMOS的硅基光波导移相器中。TCO较高的光吸收系数限制了其在移相器中的应用。提出了一种基于高迁移率的透明导电氧化物的低插入损耗硅基光波导移相器,并证明了TCO材料迁移率与其损耗密切相关。通过理论计算和数值仿真,设计了一种基于高迁移率氧化镉(CdO)材料(μ=300cm^2·V^-1·s^-1)的硅基光波导移相器。所得器件在1550nm波长实现π相移时,器件长度为127μm,插入损耗为1.4dB,调制带宽可达到300GHz。为发展高速硅基光波导移相器件提供了新思路。

Silicon-based optical waveguide phase shifters are key components in silicon-based photoelectronic systems.Transparent conductive oxide(TCO)films are expected to be applicable to the next generation of siliconbased optical waveguide phase shifters with high modulation speed,low insertion loss,and CMOS-compatibility due to their tunable permittivity under a gate voltage.However,the high optical absorption coefficient of the TCO has limited their application in electro-optic phase shifters.We propose a compact and low-insertion-loss silicon-based optical waveguide phase shifter based on TCOs with high electron mobility.We demonstrate that the mobility of the TCO material is closely related to their insertion loss.Based on theoretical calculations and numerical simulations,we propose a silicon-based optical waveguide phase shifter based on high-mobility cadmium oxide(CdO,μ=300 cm^2·V^-1·s^-1)materials.Forπ-phase shift at 1550 nm,this CdO-based phase shifter shows a low-insertion loss of 1.4 dB,device length of 127μm,and modulation bandwidth of 300 GHz.It provides a new strategy for the development of high-speed silicon-based optical waveguide phase shifters.