Free space optical communication receiver based on a spatial demultiplexer and a photonic integrated coherent combining circuit

TL;DR

This paper introduces a novel free space optical receiver using a spatial demultiplexer and photonic integrated circuit to enhance resilience against atmospheric turbulence effects like scintillation and beam wandering.

Contribution

The work presents a proof-of-concept multimode FSO receiver that coherently combines multiple spatial modes on-chip, demonstrating improved robustness to wavefront distortions.

Findings

Multimode receiver shows strong resilience to wavefront distortions.

System effectively detects optical beam modulation through random wavefront profiles.

On-chip coherent combining enhances FSO communication reliability.

Abstract

Atmospheric turbulences can generate scintillation or beam wandering phenomena that impairs free space optical (FSO) communication. In this paper, we propose and demonstrate a proof-of-concept FSO communication receiver based on a spatial demultiplexer and a photonic integrated circuit coherent combiner. The system collects the light from several Hermite Gauss spatial modes and coherently combine on chip the energy from the different modes into a single output. The FSO receiver is characterized with a wavefront emulator bench that generates arbitrary phase and intensity patterns. The multimode receiver presents a strong resilience to wavefront distortions, compared to a monomode FSO receiver. The system is then used to detect a modulation of the optical beam through a random wavefront profile.