Misalignment-Tolerant Spot-Size Converter for Efficient Coupling Between Single-Mode Fibers and Integrated Optical Receivers

We design a spot-size converter (SSC) on silicon-on-insulator (SOI) platform to interface an integrated optical receiver (IOR) with a single-mode fiber (SMF). Because of the capability of coupling higher order modes by the proposed device, the tolerance of fiber-to-waveguide misalignment is much improved. The concept is suitable for receivers consisting of multimode-compatible components such as the echelle grating demultiplexer and the Ge waveguide photodetector.