Homodyne detection for atmosphere channels

TL;DR

This paper provides a theoretical analysis of homodyne detection through turbulent atmosphere channels, addressing noise issues and proposing a monitoring technique to improve measurement accuracy.

Contribution

It introduces a systematic theoretical framework for homodyne detection in atmospheric channels and proposes a novel monitoring method to eliminate postprocessing noise.

Findings

Imperfect local-oscillator knowledge causes postprocessing noise.

Monitoring the atmospheric transmission coefficient removes postprocessing noise.

The proposed technique enhances measurement reliability in turbulent conditions.

Abstract

We give a systematic theoretical description of homodyne detection in the case where both the signal and the local oscillator pass through the turbulent atmosphere. Imperfect knowledge of the local-oscillator amplitude is effectively included in a noisy density operator, leading to postprocessing noise. Alternatively, we propose a technique with monitored transmission coefficient of the atmosphere, which is free of postprocessing noise.