High‐Speed Photodetectors on Silicon Photonics Platform for Optical Interconnect

Abstract A photodetector (PD) converts optical signals into electrical ones and is widely used in optical interconnect. High‐speed PDs are in high demand as they are necessary to meet requirements of large‐capacity optical interconnect. Many high‐performance PDs with various absorption materials and structures are demonstrated on silicon photonics platform, including germanium (Ge) PDs, germanium tin (GeSn) PDs, heterogeneous integrated III–V PDs, all silicon (Si) PDs, 2D material PDs, etc. These kinds of PDs continue to set new records of speed and open an era of ultrahigh‐speed optical interconnect. A comprehensive summary of the state‐of‐the‐art high‐speed PDs on silicon photonics platform is necessary and meaningful. In this review, the basic metrics and key process technologies for the PDs are introduced, and various types of high‐speed PDs based on silicon photonics platform are reviewed and discussed. Furthermore, the summary and perspectives are provided. It is hoped that this review can provide readers more insights into recent advances in high‐speed PDs on silicon photonics platform and contribute to the further development.