III‐Nitride Micro‐Array Integration for Photon Transceiver

Abstract III‐nitride structures offer a promising platform for high‐density and versatile photonic integration for crucial applications such as on‐chip optical communication, computing, and memory. However, III‐nitride photonic integration has suffered from complex fabrication processes, low optical output power, and low −3 dB bandwidth. Here, micro‐array integrated structure with the wavelength of 275 nm is introduced into nitride photonic integrated circuits (PICs). Solar blind micro‐array integrated chips incorporating light‐emitting diodes (LEDs) and photodetectors (PDs) greatly enhance the −3 dB bandwidth to 451 MHz under a low current density of 30 A cm −2 . Furthermore, the miniature multiple quantum wells (Mini‐MQWs) structure is incorporated into the solar‐blind nitride epilayers to effectively reduce carrier lifetime. The Al reflector design further enhances the optical confinement of integrated waveguides by 51.9%. The integrated PD demonstrates an excellent photo‐to‐dark current ratio of 6.51 × 10 5 and a self‐driven response capability of 73.3 A W −1 . Ultimately, the micro‐array integrated chips demonstrate a record on‐chip solar‐blind communication rate of 200 Mbps and nanosecond‐range transient response time. In addition, the Mini‐MQWs structure micro‐array integrated PD exhibits the bidirectional opening phenomenon of photo‐to‐dark current ratio with an increase of more than two orders of magnitude at a 6 V voltage bias, providing an interesting method for realizing efficient on‐chip full‐duplex optical communication technology.