Optical Antennas for Wavelength Division Multiplexing in Visible Light Communications beyond the Étendue Limit

This paper presents a novel fluorescent receiver for visible light communications that combines a broad field of view (FoV) with a significant gain, and simultaneously enables wavelength division multiplexing (WDM) for data communications. These characteristics are achieved by creating a receiver that includes a stack of two fluorescent optical antennas, each designed to receive a different part of the spectrum and create two separable communication channels. The device outperforms the theoretical étendue limit in terms of the combination of FoV and gain it can achieve. Furthermore, the demonstrated de‐multiplexing of blue and green spectral components enables the parallel streaming of data by WDM. Since these devices are inexpensive, simple, and compact, they can easily be integrated into portable electronic devices such as phones, tablets, and laptops. A new paradigm of optical antenna for visible light communications is presented. The antenna enables wavelength division multiplexing by separating the incident light into blue and green channel. This is done without use of filters and thus without loss of energy, while maintaining the wide field of view and gain of the fluorescent antennas.