Stokes Parameters and Dual Classical-Quantum Signaling

TL;DR

This paper introduces a new simultaneous quantum-classical communication protocol using polarization encoding with Stokes parameters, enabling secure quantum and high-throughput classical data transmission in satellite-based free-space optical networks.

Contribution

The paper presents a novel SQCC protocol that improves practicality, eliminates the need for a local oscillator, and simplifies detection, advancing the integration of quantum and classical communications.

Findings

The protocol achieves secure quantum and classical data coexistence with minimal infrastructure changes.

Theoretical and numerical analysis shows promising performance for practical implementation.

The approach reduces interference between quantum and classical signals in free-space optical links.

Abstract

Catering to emerging satellite-based free-space optical (FSO) communication networks and exploiting polarization encoding via Stokes operators, we propose a novel simultaneous quantum-classical communications (SQCC) protocol. The protocol enables the coexistence of secure quantum communications and high-throughput classical communications with minimal alterations in both the infrastructure and the energy input. Compared to the conventional SQCC protocol, our new approach provides superior practicality in the real world, eliminates the need for a separate local oscillator, and allows for the simple readout of both quantum and classical information using direct detection. The protocol also minimizes the undesirable interplay between the quantum and the classical parts of communication. We provide a detailed mathematical formulation of the protocol, along with theoretical and numerical analysis of its performance, illustrating a promising path to practical and effective realization of combined classical-quantum communications