Chip-based III-nitrides coupled structures array for multichannel data transmission

Abstract The coexistence of electroluminescence (EL) and photodetection capabilities intrinsic to III-nitride multi-quantum wells (MQWs) facilitates monolithic transceiver integration, representing a pivotal advancement for on-chip photonic links. Instead of intricate waveguide architectures, here we propose and demonstrate a simpler on-chip spatial-coupling method for low-noise, low-power multichannel chip-to-chip interconnects, using a monolithically integrated 5×3 InGaN/GaN transceiver array on silicon. Each communication cell consists of a rectangle emitter butt-coupled to a circular receiver with a 3 μm intra-gap; a 1 mm pitch suppresses inter-channel crosstalk. Experimental results indicate that the spectra have a considerable overlap between the 475-575 nm EL and the 350-500 nm photoresponse of InGaN/GaN MQW diodes. Static characterization of the individual device yields -3 dB data bandwidths of 6.65 MHz (transmit) and 0.161 MHz (receive). In contrast, the coupled pair operates at a system bandwidth of 15.34 kHz, with transmission speeds exceeding 0.7 Mbps per channel, giving an aggregate chip capacity exceeding 10.5 Mbps. Finally, independent two-channel communication is demonstrated: one lane delivers ASCII text "NJUPTB20012616," and the other streams 8-bit grayscale images without packet loss. The architecture is fully scalable, providing a compact route to high-speed visible-light communication links.