Modeling High Quantum Bit Rate QKD Systems over Optical Fiber

TL;DR

This paper investigates how chromatic dispersion affects high-speed quantum key distribution over optical fibers, emphasizing the importance of managing dispersion effects to enable secure, high-rate quantum communication systems.

Contribution

It provides an analysis of chromatic dispersion impacts on 10 Gb/s QKD systems, highlighting the need for dispersion management at high quantum bit rates.

Findings

Chromatic dispersion significantly affects 10 Gb/s QKD performance.

Managing dispersion is crucial for secure high-rate quantum communication.

Current systems operate at 1 Gb/s, with 10 Gb/s systems under research.

Abstract

There is considerable interest in finding conditions under which the quantum key distribution (QKD) propagation distances over fiber and secure key rate (SKR) are maximized for a given acceptable quantum bit error rate. One way to increase the secure key rate is to increase quantum bit rate, i.e. use shorter pulses. Short pulses propagating in a fiber are subject to temporal broadening caused by chromatic dispersion (CD) which leads to inter-symbol-interference and quantum bit-error rate increase. Current commercial QKD systems employ 1 Gb/s quantum bit rate sources, and the transition to 10 Gb/s system is being researched. While not very important in the 1 Gb/s, the effect of CD cannot be neglected in 10 Gb/s or higher quantum bit rate systems.