Non-Poissonian statistics from Poissonian light sources with application to passive decoy state quantum key distribution

TL;DR

This paper introduces a passive method to generate non-Poissonian photon pulses from Poissonian sources using linear optics and detectors, enhancing quantum key distribution without active modulation.

Contribution

A novel passive technique for preparing non-Poissonian states from Poissonian sources, simplifying decoy state implementation in quantum key distribution.

Findings

Key rates comparable to active intensity modulation methods

Passive preparation simplifies quantum key distribution protocols

Method uses only linear optics and threshold detectors

Abstract

We propose a method to prepare different non-Poissonian signal pulses from sources of Poissonian photon number distribution using only linear optical elements and threshold photon detectors. This method allows a simple passive preparation of decoy states for quantum key distribution. We show that the resulting key rates are comparable to the performance of active choices of intensities of Poissonian signals.