On the energy efficiency of Laser-based Optical Wireless Networks

TL;DR

This paper investigates the energy efficiency of laser-based indoor optical wireless networks using VCSELs, analyzing how beam size and micro lenses affect throughput and power consumption.

Contribution

It introduces a novel design for multi-user laser-based optical wireless networks with energy efficiency analysis considering beam waist and micro lens enhancements.

Findings

Energy efficiency increases with larger laser beam waist.

Micro lenses significantly improve energy efficiency.

Optimal beam size enhances network throughput.

Abstract

Optical wireless Communication (OWC) is a strong candidate in the next generation (6G) of cellular networks. In this paper, a laser-based optical wireless network is deployed in an indoor environment using Vertical Cavity Surface Emitting Lasers (VCSELS) as transmitters serving multiple users. Specifically, a commercially available low-cost VCSEL operating at 850nm wavelength is used. Considering the confined coverage area of each VCSEL, an array of VCSELs is designed to transmit data to multiple users through narrow beams taking into account eye safety regulations. To manage multi-user interference (MUI), Zero Forcing (ZF) is implemented to maximize the multiplexing gain of the network. The energy efficiency of the network is studied under different laser beam waists to find the effective laser beam size that results in throughput enhancement. The results show that the energy efficiency increases with the laser beam waist. Moreover, using micro lenses placed in front of the VCSELs leads to significant increase in the energy efficiency.