Encoding information in the mutual coherence of spatially separated light beams

TL;DR

This paper introduces mutual coherence coding, a novel method for encoding data in the mutual coherence of spatially separated light beams, offering potential advantages in cryptography and data security.

Contribution

It presents a new coding scheme based on mutual coherence, analyzes its performance metrics, and demonstrates quadratic scaling benefits for optical data transmission.

Findings

Quadratic scaling of transmitted signals with number of beams

Enhanced potential for cryptography and secure communications

Performance metrics derived for the coding scheme

Abstract

Coherence has been used as a resource for optical communications since its earliest days. It is widely used for multiplexing of data, but not for encoding of data. Here we introduce a coding scheme, which we call \textit{mutual coherence coding}, to encode information in the mutual coherence of spatially separated light beams. We describe its implementation and analyze its performance by deriving the relevant figures of merit (signal-to-noise ratio, maximum bit-rate, and spectral efficiency) with respect to the number of transmitted beams. Mutual coherence coding yields a quadratic scaling of the number of transmitted signals with the number of employed light beams, which might have benefits for cryptography and data security.