High coherence photon pair source for quantum communication

TL;DR

This paper introduces a new narrow-band, single-mode entangled photon pair source at telecom wavelengths, enabling stable quantum communication protocols with high spectral brightness and minimal active stabilization.

Contribution

The paper presents a novel single-mode, narrow-band entangled photon source based on parametric down conversion with high spectral brightness and stability for quantum communication.

Findings

Achieved spectral radiance of 0.08 pairs per coherence length with 7 mW pump power.

Realized a HOM dip demonstrating setup stability and performance.

Source allows quantum communication without active synchronization.

Abstract

This paper reports a novel single mode source of narrow-band entangled photon pairs at telecom wavelengths under continuous wave excitation, based on parametric down conversion. For only 7 mW of pump power it has a created spectral radiance of 0.08 pairs per coherence length and a bandwidth of 10 pm (1.2 GHz). The effectively emitted spectral brightness reaches 3.9*10^5 pairs /(s pm). Furthermore, when combined with low jitter single photon detectors, such sources allow for the implementation of quantum communication protocols without any active synchronization or path length stabilization. A HOM-Dip with photons from two autonomous CW sources has been realized demonstrating the setup's stability and performance.