Photonic Integrated Phase Decoder Scheme for High-Speed, Efficient and Stable Quantum Key Distribution System

TL;DR

This paper introduces a photonic integrated phase decoder scheme for high-speed, stable quantum key distribution, enhancing system efficiency and environmental robustness through a novel interferometer design.

Contribution

It proposes a new quantum phase decoder model using an integrated Michelson interferometer that improves stability and efficiency in QKD systems.

Findings

The SRMI decoder is immune to quantum channel disturbances.

The decoder can be fabricated with photonic integrated circuits.

It is suitable for gigahertz phase encoding QKD systems.

Abstract

Quantum key distribution (QKD) is gradually moving towards network applications. It is important to improve the performance of QKD systems such as photonic integration for compact systems, the stability resistant to environmental disturbances, high key rate, and high efficiency in QKD applications. In the letter, we propose a general quantum decoding model, namely orthogonal-polarizations-exchange reflector Michelson interferometer model, to solve quantum channel disturbance caused by environment. Based on the model, we give a quantum phase decoder scheme, i.e. a Sagnac configuration based orthogonal-polarizations-exchange reflector Michelson interferometer (SRMI). Besides the stability immune to quantum channel disturbance, the SRMI decoder can be fabricated with photonic integrated circuits, and suitable to gigahertz phase encoding QKD systems, and can increase the system efficiency because of the low insertion loss of the decoder.