Phase retrieval enhanced by quantum correlation

TL;DR

This paper introduces a quantum correlation-based technique to enhance phase retrieval in non-interferometric imaging, improving sensitivity and reducing photon dose in microscopy and X-ray imaging.

Contribution

It presents a novel method leveraging entanglement for quantitative phase retrieval without interferometry, compatible with existing technology and wide field operation.

Findings

Enables sub-shot-noise readout of phase information

Operates with small spatial coherence and wide field mode

Reduces photon dose in imaging applications

Abstract

Quantum correlation, such as entanglement and squeezing have shown to improve phase estimation in interferometric setups on one side, and non-interferometric imaging scheme of amplitude object on the other. In the last case, quantum correlation among a pair of beams leads to a sub-shot-noise readout of the image intensity pattern, where weak details, otherwise hidden in the noise, can be appreciated. In this paper we propose a technique which exploits entanglement to enhance quantitative phase retrieval of an object in a non-interferometric setting, i.e only measuring the propagated intensity pattern after interaction with the object. The method exploits existing technology, it operates in wide field mode, so does not require time consuming raster scanning and can operate with small spatial coherence of the incident field. This protocol can find application in optical microscopy and X-ray imaging, reducing the photon dose necessary to achieve a fixed signal-to-noise ratio.