High-Speed InGaP/AlGaAs Avalanche Photodiodes for LED-Based Visible Light Communication

We report on the demonstration of an InGaP/AlGaAs heterojunction avalanche photodiode (APD) with an aluminum composition of 0.8, optimized for high-speed visible-light detection. The APD achieves a 3-dB bandwidth of 2.25 GHz at a multiplication gain of 72, corresponding to a gain-bandwidth product (GBP) of 162 GHz. It exhibits low dark current, low excess noise, and high multiplication gain, highlighting its suitability for high-performance optical applications. To showcase its potential, we integrated the APD into a visible-light communication system with a GaN micro-LED transmitter, achieving a data rate exceeding 1063 Mb/s. These findings highlight the promise of InGaP/AlGaAs APDs for advancing high-speed visible-light communication technologies.