Tunable cavity-enhanced photon pairs source in Hermite-Gaussian mode

TL;DR

This paper demonstrates the generation of narrow-bandwidth photon pairs in Hermite-Gaussian modes using a type-I optical parametric oscillator, enabling advanced quantum communication applications.

Contribution

It introduces a method to produce photon pairs in high-order spatial modes with tunable properties in a cavity-enhanced setup.

Findings

Photon pairs with bandwidths of 11.4 MHz and 20.8 MHz were generated.

Non-classical properties of HG modes were verified through correlation measurements.

The source is suitable for storage in cold atomic ensembles.

Abstract

The spatial modes of light have grasped great research interests because of its great potentials in optical communications, optical manipulation and trapping, optical metrology and quantum information processing. Here we report on generating of photon pairs in Hermite-Gaussian (HG) mode in a type-I optical parametric oscillator (OPO) operated far below threshold. The bandwidths of the photon pairs are 11.4 MHz and 20.8MHz for two different HG modes respectively, which is capable to be stored in cold Rubidium atomic ensembles. From correlation measurements, non-classical properties of HG modes in different directions are verified by tuning the cavity. Our study provides an effective way to generate photon pairs with narrow bandwidth in high order spatial modes for high dimensional quantum communication.