Experimental construction of a versatile four-photon source

TL;DR

This paper details the construction and testing of a highly versatile four-photon source capable of generating various entangled states, supporting advanced quantum communication protocols with tunable properties.

Contribution

It introduces a flexible multi-photon source with tunable entanglement and purity, along with comprehensive construction and alignment procedures.

Findings

Successful generation of up to four photons for quantum protocols

Ability to produce separable, partially-entangled, or maximally-entangled photon pairs

Thorough testing confirms the source's versatility and reliability

Abstract

The paper discusses technical aspects of constructing a highly versatile multi-photon source. The source is able to generate up to four photons which is sufficient for a large number of quantum communications protocols. It can be set to generate separable, partially-entangled or maximally-entangled photon pairs with tunable amount of purity. Furthermore, the two generated pairs can be prepared in different quantum states. In this paper, we provide all the necessary information needed for construction and alignment of the source. To prove the working principle, we also provide results of thorough testing.