Fluorescent Fiber-Based Optical Antenna for Visible Light Communication Applications

Fiber-based optical antennas are useful for efficient light reception at the receiver in visible light communication (VLC) systems. It combines the principles of fiber optics and antenna technology to achieve high-speed wireless communication. These antennas serve as the interface between the free-space optical channel and the photo-detector (PD), allowing efficient light coupling onto the PD. In this paper, fluorescent optical fiber antennas are designed by combining multiple short-length fibers parallelly to increase the collection of light at the receiver end of the VLC system. Two different types of fluorescent optical fibers, namely R-3 fibers and YS-2 fibers are used in the VLC system. Each type of these two fibers is used to create one single-stage antenna. Also, a dual-stage fluorescent fiber antenna is made by combining both YS-2 and R-3 fibers. The communication performances of single and dual-stage antennas are compared. It is found that the single-stage fiber antenna performs better, contrary to intuition. The single-stage YS-2 fiber-based antenna has exhibited higher efficiency, achieving a data rate of 120 Mbps at a distance of 10 cm, surpassing the performance of the single-stage R-3 fiber-based antenna (60 Mbps) and the dual-stage antenna (36 Mbps). The drop in data speed for dual-stage fiber antenna is attributed to lower received signal power, which arises from inefficient light coupling at the fiber-to-fiber interface. The light coupling from the first-stage fibers to the second-stage fibers is inefficient, which leads to reduced light output from the second-stage fibers onto the PD. As a result, despite having a larger active area, dual-stage antennas fail to perform better in our experiments. So, dual-stage fiber antennas do not guarantee better performance.