Randomly poled crystals as a source of photon pairs

TL;DR

This paper investigates the use of randomly poled nonlinear crystals as sources of entangled photon pairs, demonstrating their broad spectral bandwidth, linear scaling of generation rates, and potential for ultra-short entanglement times, comparable to chirped structures.

Contribution

It introduces randomly poled crystals as effective photon-pair sources with analytically supported properties and compares them to chirped periodically-poled structures.

Findings

Photon-pair generation rates scale linearly with the number of domains.

Entanglement times as short as several femtoseconds are achievable.

Randomly poled crystals produce ultra broad-band entangled photon fields.

Abstract

Generation of photon pairs from randomly poled nonlinear crystals is investigated using analytically soluble model and numerical calculations. Randomly poled crystals are discovered as sources of entangled ultra broad-band signal and idler fields. Their photon-pair generation rates scale linearly with the number of domains. Entanglement times as short as several fs can be reached. Comparison with chirped periodically-poled structures is given and reveals close similarity.