Subwavelength-Structure-Assisted Ultracompact Polarization-Handling Components on Silicon

Silicon photonic integrated circuits with the abilities of large-scale integration and low-cost fabrication are one of the most promising technologies for various emerging applications. For silicon photonic integrated circuits, which are usually polarization-sensitive, polarization-handling is of critical importance as a key manipulation of light. Basically, ultracompact polarization-handling devices with high performances in a broad band are highly desired. In this paper, a review is given for recent progresses of high-performance silicon polarization-handling devices assisted with subwavelength structures (SWSs), which introduce more degrees of freedom (DoFs) in design. In Section II, the fundamental of both regular and disordered SWSs with different DoFs is introduced and discussed. Different kinds of polarization-handling devices are presented in Section III, including polarizers, polarization beam splitters, polarization rotators/polarization-splitter-rotators, dual-polarization devices. Finally, the challenges and the opportunities of silicon polarization-handling devices are discussed in Section IV.