Silicon-Based Waveguide Technology for Wavelength Division Multiplexing

This chapter reviews the application of silicon-based planar waveguide components for wavelength division multiplexing (WDM) and demultiplexing. The polarization dependent properties and dominant waveguide loss mechanisms in both silica-on-silicon and silicon-on-insulator (SOI) waveguides are described, and the technologies developed to control loss and eliminate polarization dependence in both material platforms are presented and compared. Although less mature, the development of high index contrast devices in SOI closely parallels the evolution of silica glass waveguide technology. Many of the important design challenges have been resolved, and the performance of SOI-based integrated optic components is rapidly approaching that of the silica waveguide system.