GaN-based Series Hybrid LED Array: A Dual-function Light Source with Illumination and High-speed Visible Light Communication Capabilities

We propose and demonstrate a GaN-based series-driven hybrid light emitting diode (SH-LED) device in which broad-area and micro-LED components are interconnected for simultaneous illumination and high-speed visible light communication (VLC) applications. Through theoretical analysis based on an equivalent electrical circuit model and characterization from a fabricated exemplar device with blue emission, it is shown that SH-LEDs combine the advantages of broad-area and micro-LED components by offering high direct-current (DC) optical power output and a fast frequency response. The application of this device to VLC is demonstrated through both the point-to-point and 9 $^\circ$ divergence-angle coverage systems at 3 m transmission distance adopting a DC-biased optical-orthogonal frequency-division multiplexing modulation scheme. Compared with a point-to-point system using a single micro-LED, that our initial demonstrator SH-LED achieves the same data transmission rate of 3.39 Gbps at forward error correction (FEC) floor of 3.8 $\times 10^{-3}$ , but the received DC optical power is improved by over 3 times. For the area coverage system, up to 1.56 Gbps data transmission rates at a FEC floor of 3.8 $\times 10^{-3}$ are accomplished by using this device, associated with over 4 times higher received DC optical power compared with that using a single micro-LED.