A Two-Stage Fluorescent Antenna for Visible Light Communication Uplinks

Previous work on fluorescent antennas in visible light communications (VLC) has primarily focused on downlink receivers, which have to be compact. In contrast, uplink receivers can potentially occupy much larger areas. A convenient and inexpensive approach to increasing the antenna's area is to use a large array of fluorescent optical fibers. The challenge is then to couple this array to a much smaller photodiode. To address this challenge an antenna that consists of two stages is demonstrated. The first of these stages is a large array of fluorescent fibers that can absorb light from the uplink transmitter. The fluorescence from this array is then coupled into the second stage, which is a single fluorescent fiber that can absorb the fluorescence from the first stage. The diameter of this fiber means that it can be effectively coupled to a photodiode. Results are presented which demonstrate this concept by measuring the system's signal gain, field of view (FoV), bandwidth, and data transmission performance.