Towards 20-Gbps Single-Chip Space Division Multiplexing Visible Light Communication Based on a Low-Crosstalk micro-LED Array

High-speed visible light communication (VLC) using light-emitting diodes (LEDs) is a promising candidate for 6 G networks. Space division multiplexing (SDM) using large LED arrays is expected to significantly enhance VLC system data rates. However, current SDM systems based on multiple packaged LEDs lack the advantage of integration, and their data rate is limited by the low bandwidth of packaged LEDs. This paper presents a high-speed single-chip SDM VLC system using a violet micro-LED array. By applying a deep etching process, each micro-LED in the array is electrically isolated, mitigating the crosstalk effects that typically degrade performance. Simulation analysis of both optical and electrical crosstalk reveals that optical crosstalk is negligible when proper optical alignment is achieved, and electrical crosstalk is significantly reduced with the non-common-n structure. A record data rate of 19.3 Gbps over a distance of 1.2 meters is achieved, which is the highest data rate for LED-based SDM VLC systems. This system, using a high-integrated single-chip micro-LED array, achieves over 9.5 Gbps per micro-LED, the highest data rate for a single violet micro-LED, demonstrating the potential for future large-scale high-speed VLC systems with minimal crosstalk.