High-efficiency, 10 GHz bandwidth resonant-cavity-enhanced silicon photodetectors operating at 850 nm wavelength

摘要

Resonant-cavity-enhanced (RCE) photodetectors have been the focus of extensive research over the past decade in the design of high bandwidth-efficiency product devices [1,2]. Silicon-based photodetectors for applications in optical communications in the near-IR wavelength range between 800-900 nm suffer from low bandwidth-efficiency products due to the long absorption length necessitated by the small absorption coefficient. Increasing the bandwidth-efficiency product is the inherent benefit of a RCE structure, which relies on the constructive interference of a Fabry-Perot cavity to enhance the optical field inside the photodetector at specific wavelengths. For semiconductor photodetectors, such a resonant cavity can be formed using a buried reflector consisting of alternating layers of semiconductors and the air/semiconductor top interface. Due to the availability of heterostructures, compound semiconductors have been the focus of RCE photodetector development [1]. Formation of buried mirrors and resonant cavities have remained as a challenge in Si technology.