Quantum imaging of a polarisation sensitive phase pattern with hyper-entangled photons

TL;DR

This paper demonstrates a quantum imaging technique using hyper-entangled photons to visualize a transparent, polarisation-sensitive phase pattern without photon absorption, through joint measurements on entangled photon pairs.

Contribution

It introduces a long-path quantum imaging method employing hyper-entangled photon pairs with momentum and polarisation, enabling imaging of transparent phase patterns without direct interaction.

Findings

Successful quantum imaging of a polarisation-sensitive phase pattern.

Use of hyper-entangled photons for joint measurement-based imaging.

Detailed theoretical and experimental validation of the method.

Abstract

A transparent polarisation sensitive phase pattern makes a polarisation dependent transformation of quantum state of photons without absorbing them. Such an invisible pattern can be imaged with quantum entangled photons by making joint quantum measurements on photons. This paper shows a long path experiment to quantum image a transparent polarisation sensitive phase pattern with hyper-entangled photon pairs involving momentum and polarisation degrees of freedom. In the imaging configuration, a single photon interacts with the pattern while the other photon, which has never interacted with the pattern, is measured jointly in a chosen polarisation basis and in a quantum superposition basis of its position which is equivalent to measuring its momentum. Individual photons of each hyper-entangled pair cannot provide a complete image information. The image is constructed by measuring the polarisation state and position of the interacting photon corresponding to a measurement outcome of the non-interacting photon. This paper presents a detailed concept, theory and free space long path experiments on quantum imaging of polarisation sensitive phase patterns.