Broadband pumped polarization entangled photon-pair source in a linear beam displacement interferometer

TL;DR

This paper presents an experimental setup for generating polarization-entangled photon pairs using a broadband laser diode and a PPKTP crystal within a linear beam-displacement interferometer, achieving high pair rates and visibility.

Contribution

It introduces a novel polarization-entangled photon-pair source utilizing broadband pumping and a linear interferometer, enabling high pair rates with simple, scalable components.

Findings

Pair rate of 0.56 Mpairs/s/mW in a single mode

Polarization visibility of 97.7% over 100 nm spectral range

Pathway to gigacount rates with high-power lasers and multiplexed detectors

Abstract

We experimentally demonstrate a source of polarization entangled photon-pairs based on a single periodically-poled potassium titanyl phosphate (PPKTP) crystal pumped with a broadband, free running laser diode.The crystal is placed within a linear beam-displacement interferometer, and emits photon-pairs based ontype-0 spontaneous parametric downconversion (SPDC). We observe pair rates of 0.56 Mpairs/s/mW in a single spatial mode with a polarization visibility of 97.7% over a spectral range of 100 nm. This experiment demonstrates a pathway towards observing Gigacount rates of polarization entangled photon pairs by using high-power free-running laser diodes with fast multiplexed detectors.