Total Internal Reflection Lens for Optical Wireless Receivers

Abstract

This work considers the use of a freeform total internal reflection (TIR) lens for optical concentration and provides for the first time experimental results in the context of optical wireless communications (OWC). The lens is placed on a surface-mounted device (SMD) avalanche photodiode (APD) to minimize position tolerances and simplify assembly. The lens achieves a concentration ratio of go = 44.7 (16.5 dB) within the FOV center and exhibits an acceptance angle of ±5°. The TIR lens approach is validated by comparing eye diagrams and bit error ratios (BER) of a receiver with and without a TIR lens. For the measurements, non-return-to-zero (NRZ) on-off keying (OOK) signals are transmitted with a data rate of 1.289 Gbit/s.

A Superimposed QD-Based Optical Antenna for VLC: White LED Source

“…Moreover, there is an essential need to dissolve the problem of spectrum scarcity and limited channel capacity in today’s exponentially growing wireless communication demand [ 2 ]. Many attractive characteristics of optical wireless communication (OWC) and visible light communication (VLC), such as real-time data transfer with high reliability, lower electromagnetic interference, more secure indoor wireless access, unlimited bandwidth, and better area spectral efficiency, make them promising successors of radio frequency (RF) communication [ 2 , 3 ]. VLC provides simple, flexible, and cost-effective OWC transmission [ 4 ] and is an auspicious technology for sixth generation (6G) networks because of the broad unlicensed spectrum [ 2 ].…”

“…Second, the Cassegrain antenna has a small field of view (FOV) and does not suit the VLC system [ 24 ]. Third, spherical and aspherical lenses (for example hemispherical lenses) have wide FOV but small gain [ 3 , 6 ]. Fourth, a compound parabolic concentrator (CPC) provides either small gain with wide FOV or significant gain with limited FOV [ 23 , 25 ].…”