Photon Efficiency Limits in the Presence of Background Noise

TL;DR

This paper establishes theoretical limits on the photon information efficiency of deep-space optical communication systems considering background noise, highlighting the impact of noise strength and detection methods on efficiency.

Contribution

It provides a theoretical analysis of the maximum photon information efficiency under background noise constraints, assuming scalable modulation and photon counting detection.

Findings

Maximum PIE depends logarithmically on background photons

Background noise significantly limits communication efficiency

Detection method assumptions influence the efficiency bounds

Abstract

We identify theoretical limits on the photon information efficiency (PIE) of a deep-space optical communication link constrained by the average signal power and operated in the presence of background noise. The ability to implement a scalable modulation format, Geiger-type direct photon counting detection, and complete decoding of detection events are assumed in the analysis. The maximum attainable PIE is effectively determined by the background noise strength and it exhibits a weak, logarithmic dependence on the detected number of background photons per temporal slot.