NOVEL 1-TO-N WAY INTEGRATED OPTICAL BEAM-SPLITTERS USING SYMMETRICAL MODE MIXING IN GAAS/ALGAAS MULTIMODE WAVE-GUIDES

We report the demonstration of novel GaAs/AlGaAs integrated optical 1-to-N way beam splitters which use symmetric mode mixing in center-fed multimode planar waveguides. Each device has one single-mode input guide, a carefully chosen length of parallel sided multimode guide, and N equally spaced single-mode output guides. The mixing of symmetric modes shares the input light equally between the output guides by a symmetric form of the self-imaging process. We demonstrate experimentally that this type of beam splitter can be used to divide power equally, with high accuracy and low loss, between the N output guides, for values of N between 2 and 20.