Reconfigurable beam system for non-line-of-sight free-space optical communication

TLDR

Light is steered around obstacles blocking the direct communication pathway and reaches a receiver after reflecting off a diffuse surface. In this paper, we propose a reconfigurable beam‑shaping system to permit energy‑efficient non‑line‑of‑sight free‑space optical communication. A coherent array optical transmitter spatially shapes the wavefront of light incident on a diffuse surface to enhance the amount of diffusely reflected light reaching the receiver. Synthetic NLOS experiments over a 20° angular range demonstrate a record‑breaking 30‑Gbit/s orthogonal frequency‑division multiplexing signal transmitted over a diffused optical wireless link with a >17‑dB gain.

Abstract

In this paper, we propose a reconfigurable beam-shaping system to permit energy-efficient non-line-of-sight (NLOS) free-space optical communication. Light is steered around obstacles blocking the direct communication pathway and reaches a receiver after reflecting off of a diffuse surface. A coherent array optical transmitter (CAO-Tx) is used to spatially shape the wavefront of the light incident on a diffuse surface. Wavefront shaping is used to enhance the amount of diffusely reflected light reaching the optical receiver. Synthetic NLOS experiments for a signal reflected over an angular range of 20° are presented. A record-breaking 30-Gbit/s orthogonal frequency-division multiplexing signal is transmitted over a diffused optical wireless link with a >17-dB gain.