Theory of high gain cavity-enhanced spontaneous parametric down-conversion

TL;DR

This paper develops an analytic theoretical framework for cavity-enhanced spontaneous parametric down-conversion at arbitrary gain levels, enabling better understanding and design of quantum light sources for advanced quantum technologies.

Contribution

It extends existing models to arbitrary gain and finesse, providing accurate analytic tools for describing cavity-enhanced SPDC in quantum optics.

Findings

Increased coherence observed due to stimulated SPDC.

Analytic Bogoliubov transformations derived for arbitrary gain.

Model accurately predicts field correlations in cavity-enhanced SPDC.

Abstract

We compute the output of multimode cavity-enhanced spontaneous parametric down-conversion (SPDC) for sub-threshold, but otherwise arbitrary, gain. We find analytic Bogoliubov transformations that allow us to calculate arbitrary field correlation functions, including the second-order intensity correlation function $G^{(2)}(T)$. The results show evidence of increased coherence due to stimulated SPDC. We extend an earlier model [Lu and Ou, Phys. Rev. A, 62, 033804 (2000)] to arbitrary gain and finesse, and show the extension gives accurate results in most scenarios. The results will allow simple, analytic description of cavity-based nonclassical light sources for quantum networking, quantum-enhanced sensing of atoms and generation of highly non-classical field states