Phosphorous Diffuser Diverged Blue Laser Diode for Indoor Lighting and Communication

Abstract

An advanced light-fidelity (Li-Fi) system based on the blue Gallium nitride (GaN) laser diode (LD) with a compact white-light phosphorous diffuser is demonstrated for fusing the indoor whitelighting and visible light communication (VLC). The phosphorous diffuser adhered blue GaN LD broadens luminescent spectrum and diverges beam spot to provide ample functionality including the completeness of Li-Fi feature and the quality of white-lighting. The phosphorous diffuser diverged white-light spot covers a radiant angle up to 120 degrees with CIE coordinates of (0.34, 0.37). On the other hand, the degradation on throughput frequency response of the blue LD is mainly attributed to the selffeedback caused by the reflection from the phosphor-air interface. It represents the current state-ofthe- art performance on carrying 5.2-Gbit/s orthogonal frequency-division multiplexed 16-quadratureamplitude modulation (16-QAM OFDM) data with a bit error rate (BER) of 3.1 x 10(-3) over a 60-cm freespace link. This work aims to explore the plausibility of the phosphorous diffuser diverged blue GaN LD for future hybrid white-lighting and VLC systems.