Effects of Design Geometries and Nonlinear Losses on Gain in Silicon Waveguides With Erbium-Doped Regions

Silicon waveguides integrated with doped dielectric gain media may allow the design of planar light sources with electronic control. In this paper, the effects of design geometries and nonlinear losses on the gain in crystalline silicon waveguides with erbium-doped regions are investigated. We show that by using multitrench geometries, the power confinement can be increased and higher gain-to-nonlinear-loss ratio achieved. Net gain can be improved as much as 0.38 dB/cm in multitrench waveguides compared to single-trench waveguides.