Spectrally pure single photons at telecommunications wavelengths using commercial birefringent optical fiber

Opt Express. 2020 Feb 17;28(4):5147-5163. doi: 10.1364/OE.383704.

Abstract

We report a bright and tunable source of spectrally pure heralded single photons in the telecom O-Band, based on cross-polarized four wave mixing in a commercial birefringent optical fiber. The source can achieve a purity of 85%, heralding efficiency of 30% and a coincidence-to-accidentals ratio of 108. Furthermore, through the measurements of joint spectral intensities, we find that the fiber is homogeneous over at least 45 centimeters and thus can potentially realize 4 sources that can produce identical quantum states of light. This paves the way for a cost-effective fiber-optic approach to implement multi-photon quantum optics experiments.