Monolithic Reflector-Integrated Waveguide Photodetector with Optical Mesa Isolation

Abstract Herein, we propose a monolithic reflector-integrated waveguide photodetector with optical isolation between photosensitive mesa and N-contact mesa for achieving a high efficiency bandwidth product. In the proposed photodetector, the photosensitive mesa is optically isolated but electrically connected with the N-contact mesa; this is achieved by etching a portion of the core layer to form a groove on each side of the photosensitive mesa, enhancing the binding of the waveguide to optical power. Furthermore, a mesa is formed separate from the N-contact mesa at the end of the waveguide, and the metal film is deposited to act as a mirror, thereby increasing the effective absorption length of the device. Consequently, the mutual tradeoff between the bandwidth and quantum efficiency of the photodetector could be alleviated.