GaAs/AlGaAs polarization splitting directional couplers

Abstract

Directional couplers are building blocks for m any guided wave devices in integrated optics and optoelectronics. They have been used as switches, modulators, wavelength filters, power dividers, wavelength m ultiplexer-dem ultiplexers, and are im portant com ponents for future switching networks. T he ability to control polarization allows fu rther flexibility in integration of optoelectronic com ponents. In this thesis, we present our work on the design, fabrication and characterization o f G aA s/A IG aA s polarization splitting directional couplers. W e have designed a directional coupler operating at 1.55 ¡.tm wavelength using a G aA s/A IG aA s heterostructure, th at have different coupling lengths for T E and T M polarized guided modes. T he device passively separates the T E and T M polarized guided modes entering the device at the sam e input port, at the output ports. M etal electrodes placed on the waveguides allowed for control of polarization.