Shaping the joint spectrum of down-converted photons through optimized custom poling

TL;DR

This paper introduces a method to engineer the joint spectrum of photon pairs generated via spontaneous parametric down conversion by optimizing the poling configuration of a crystal, enabling tailored phase-matching for pure single-photon creation.

Contribution

It presents a novel optimization scheme using simulated annealing to customize crystal poling, allowing arbitrary shaping of the phase-matching function for quantum optics applications.

Findings

Optimized poling configurations enable tailored joint spectra.

The method achieves near-arbitrary shaping of phase-matching functions.

Provided C++ code facilitates experimental implementation.

Abstract

We present a scheme for engineering the joint spectrum of photon pairs created via spontaneous parametric down conversion. Our method relies on customizing the poling configuration of a quasi-phase-matched crystal. We use simulated annealing to find an optimized poling configuration which allows almost arbitrary shaping of the crystal's phase-matching function. This has direct application in the creation of pure single photons---currently one of the most important goals of single-photon quantum optics. We describe the general algorithm and provide code, written in C++, that outputs an optimized poling configuration given specific experimental parameters.