Poissonian communications: free space optical data transfer at the few-photon level

TL;DR

This paper introduces a simple, low-power free-space optical communication system operating at the few-photon level, capable of high-rate data transfer and noise resilience, suitable for nano-satellite applications.

Contribution

It presents a novel self-synchronized optical communication system using semiconductor devices and temporal encoding at extremely low light levels, advancing practical quantum-level data transfer.

Findings

Data rates up to 100 kb/s at 8.25 pW received power

Operation in high background noise conditions

Demonstration between nano-satellite simulators

Abstract

Communicating information at the few photon level typically requires some complexity in the transmitter or receiver in order to operate in the presence of noise. This in turn incurs expense in the necessary spatial volume and power consumption of the system. In this work we present a self-synchronised free-space optical communications system based on simple, compact and low power consumption semiconductor devices. A temporal encoding method, implemented using a gallium nitride micro-LED source and a silicon single photon avalanche photo-detector (SPAD) demonstrates data transmission at rates up to 100 kb/s for 8.25 pW received power, corresponding to 27 photons per bit. Furthermore, the signals can be decoded in the presence of both constant and modulated background noise at levels significantly exceeding the signal power. The systems low power consumption and modest electronics requirements are demonstrated employing it as a communications channel between two nano-satellite simulator systems.