Tailored photon-pair generation in optical fibers

TL;DR

This paper demonstrates the control of spectral properties of photon pairs generated in microstructured fibers through dispersion engineering, enabling high-purity heralded single photons for quantum applications.

Contribution

It introduces a method to tailor photon-pair spectral structures via fiber fabrication, achieving high purity without filtering, advancing quantum light source development.

Findings

Achieved 85.9% purity in photon pairs experimentally.

Designed fibers with specific dispersion to control spectral correlations.

Theoretical analysis suggests potential for 94.5% purity with longer fibers.

Abstract

We experimentally control the spectral structure of photon pairs created via spontaneous four-wave mixing in microstructured fibers. By fabricating fibers with designed dispersion, one can manipulate the photons' wavelengths, joint spectrum, and, thus, entanglement. As an example, we produce photon-pairs with no spectral correlations, allowing direct heralding of single photons in pure-state wave packets without filtering. We achieve an experimental purity of $85.9\pm1.6%$, while theoretical analysis and preliminary tests suggest 94.5% purity is possible with a much longer fiber.