Phase-Subtractive Interference and Noise-Resistant Quantum Imaging with Two Undetected Photons

TL;DR

This paper introduces a quantum interference technique using four-photon states that enables phase imaging without detecting the illuminating photons, offering noise resistance and phase fluctuation immunity.

Contribution

It demonstrates a novel quantum interference phenomenon with undetected photons, enabling noise-resistant quantum imaging without phase sensitivity to detected photons.

Findings

Interference pattern is independent of detected photons' phases.

The technique is immune to phase fluctuations in the interferometer.

Allows imaging without detecting photons that illuminate the object.

Abstract

We present a quantum interference phenomenon in which four-photon quantum states generated by two independent sources are used to create a two-photon interference pattern without detecting two of the photons. Contrary to the common perception, the interference pattern can be made fully independent of phases acquired by the photons detected to construct it. However, it still contains information about spatially dependent phases acquired by the two undetected photons. This phenomenon can also be observed with fermionic particles. We show that the phenomenon can be applied to develop an interferometric, quantum phase imaging technique that is immune to uncontrollable phase fluctuations in the interferometer and allows image acquisition without detecting the photons illuminating the object.