Spatially multiplexed single-photon sources based on incomplete binary-tree multiplexers

TL;DR

This paper introduces two new types of spatially multiplexed single-photon sources using incomplete binary-tree multiplexers, demonstrating they can surpass complete multiplexers in single-photon probability, especially with advanced optical components.

Contribution

The paper presents novel incomplete binary-tree multiplexers for single-photon sources, optimizing their design for higher efficiency using a comprehensive statistical analysis.

Findings

Incomplete multiplexers can achieve higher single-photon probabilities than complete ones.

Output-extended incomplete multiplexers outperform input-extended ones in certain parameters.

Single-photon probabilities above 0.93 are feasible with current optical technology.

Abstract

We propose two novel types of spatially multiplexed single-photon sources based on incomplete binary-tree multiplexers. The incomplete multiplexers are extensions of complete binary-tree multiplexers, and they contain incomplete branches either at the input or at the output of them. We analyze and optimize these systems realized with general asymmetric routers and photon-number-resolving detectors by applying a general statistical theory introduced previously that includes all relevant loss mechanisms. We show that the use of any of the two proposed multiplexing system can lead to higher single-photon probabilities than that achieved with complete binary-tree multiplexers. Single-photon sources based on output-extended incomplete binary-tree multiplexers outperform those based on input-extended ones in the considered parameter ranges, and they can in principle yield single-photon probabilities higher than 0.93 when they are realized by state-of-the-art bulk optical elements.