Nonlocal cancellation of dispersion in Franson interferometry

TL;DR

This paper demonstrates a novel method to cancel femtosecond-level dispersion in a fiber-based Franson interferometer by inverting the differential dispersion sign in one arm, significantly improving quantum visibility.

Contribution

It introduces the first experimental demonstration of nonlocal dispersion cancellation in a fiber-based Franson interferometer, enhancing entanglement quality for quantum information processing.

Findings

Achieved 99.6% quantum visibility.

Restored entanglement quality comparable to polarization entanglement.

Demonstrated effective femtosecond-level dispersion cancellation.

Abstract

Dispersion and its cancellation in entanglement-based nonlocal quantum measurements are of fundamental and practical interests. We report the first demonstration of cancellation of femtosecond-level dispersion by inverting the sign of the differential dispersion between the long and short paths in only one arm of a fiber-based Franson interferometer. We restore the otherwise limited quantum visibility to an unprecedented 99.6%, and put time-energy entanglement at the same level of quality as polarization entanglement for use in quantum information processing applications.