Self-Adaptive Integrated Photonic Receiver for Turbulence Compensation in Free Space Optical Links

TL;DR

This paper introduces a self-adaptive silicon photonic receiver that dynamically compensates for atmospheric turbulence in free space optical links, improving signal quality and robustness in turbulent conditions.

Contribution

It presents an integrated, real-time adaptive optical receiver with a 2D antenna array and programmable optical processor, enabling efficient turbulence compensation in FSO systems.

Findings

Effective turbulence compensation demonstrated at 10 Gbit/s

Operates under simulated outdoor turbulence conditions

Scalable and compatible with existing fiber transceivers

Abstract

In Free Space Optical (FSO) communication systems, atmospheric turbulence distorts the propagating beams, causing a random fading in the received power. This perturbation can be compensated using a multi-aperture receiver that samples the distorted wavefront on different points and adds the various signals coherently. In this work, we report on an adaptive optical receiver that compensates in real time for scintillation in FSO links. The optical front-end of the receiver is entirely integrated in a silicon photonic chip hosting a 2D Optical Antenna Array and a self-adaptive analog Programmable Optical Processor made of a mesh of tunable Mach-Zehnder interferometers. The photonic chip acts as an adaptive interface to couple turbulent FSO beams to single-mode guided optics, enabling energy and cost-effective operation, scalability to systems with a larger number of apertures, modulation-format and data-protocol transparency, and pluggability with commercial fiber optics transceivers. Experimental results demonstrate the effectiveness of the proposed receiver with optical signals at a data rate of 10 Gbit/s transmitted in indoor FSO links where different turbulent conditions, even stronger than those expected in outdoor links of hundreds of meters, are reproduced.