Long-Range Optical Wireless Communication System Based on a Large-Area, Q-Dots Fluorescent Antenna

Fluorescent concentrators (FCs) have been recently proposed as optical condensers for visible light communications (VLC) and optical wireless communication (OWC) receivers, with advantages over conventional optical stages in terms of optical gain and field of view (FoV). However, the use of FC-based receivers in real-world scenarios is hampered by the need for large resilience of the involved chromophores to sunlight exposure, and availability of large-area FC substrates with suitable optochemical properties. This paper presents an innovative OWC system, based on a high-power blue LED and a large-area FC-based on CuInS2 quantum dots (Q-Dots) as receiving optical stage. A thorough characterization of the FC material in terms of conversion efficiency, temporal response, and FoV is provided, along with a full set of outdoor measurements. The combination of the Q-Dots fluorophores chemico-physical properties with the strong DC rejection granted by the design receiver stage allows error-free VLC link distances up to 60 m and baud rates up to 1 Mb/s. This work represents the first demonstration of long-range VLC links under strong solar irradiance using large-area FC antennas and paves the way to deployment of long-range free-space optical links with minimal susceptibility to misalignments and pointing instabilities between receiver and transmitter.