White-lighting and WDM-VLC system using transmission gratings and an engineered diffuser

A white-lighting and wavelength-division-multiplexing (WDM)-visible light communication (VLC) system with over 20 m of free-space distance and 3 m of lighting distance is demonstrated via a red/green/blue (R/G/B) triple-source polarization-multiplexing scheme, transmission gratings, and an engineered diffuser with a double-convex lens. Integrating four-level pulse amplitude modulation (PAM4) with a triple-source polarization-multiplexing scheme, the aggregate transmission rate is noticeably enhanced to 300 Gb/s [ 50 G b / s P A M 4 / s o u r c e × 3 s o u r c e s × 2 p o l a r i z a t i o n s ( p - and s -polarizations)]. White-light is produced by multiplexing the R/G/B lights with two transmission gratings and separated by demultiplexing them using the other two transmission gratings. By adopting an engineered diffuser with a double-convex lens, the white-light is diffused over 3 m of free-space distance to provide general white-light illumination ( > 100 l u x ). This demonstrated white-lighting and WDM-VLC system meets a high aggregate transmission rate with a qualified indoor lighting target. It opens up a new category for lighting and communication.