多功能2×2 GaAs/GaAlAs多模干涉型光开关分析

Analysis of Multi-Functional 2×2 GaAs/GaAlAs Optical Switch Based on the Multimode Interference

提出了一种基于深刻蚀脊形光波导带模斑转换器的多功能 2× 2GaAs/GaAlAs多模干涉型光开关 ,并用变量变换级数展开法及三维有限差分束传播法对其进行了模拟分析与优化设计 .结果表明 ,通过控制多模波导中央的两段Schottky电极 ,器件可实现交叉态、直通态及 3dB耦合器功能 ,并有较大的制作容差、较宽的工作带宽 ,只须一个多模波导 ,器件结构紧凑 .采用深刻蚀脊形光波导能够满足多模干涉型器件的精确自镜像要求 ,并使输入 /输出光波导在单模工作下有较大的横截面 ,较低的弯曲损耗及较小的耦合串扰 .通道末端引入的模斑转换器可方便地与单模光纤连接耦合 .

A multi functional 2×2 multimode interference optical switch based on the deep etched GaAs/GaAlAs optical rib waveguide with spot size converter is proposed and analyzed by using the variable transformed series expansion method and three dimensional finite difference beam propagation method.As a result,the present device can operate in various kinds of output schemes including cross and bar state as well as 3dB coupler by controlling the Schottky electrode located in the center of the only multimode waveguide with the advantages of compactness,high design tolerance,and large optical bandwidth.Moreover,the deep etched optical rib waveguide satisfies the requirement of the accurate self imaging,greatly reduces the bent loss,and has large cross section under the single mode condition.In addition,the spot size converter introduced in the ends of the input/output channels can be conveniently coupled with the single mode fiber.