Quantum Imaging and Metrology with Undetected squeezed Photons: Noise Canceling and Noise Based Imaging

TL;DR

This paper presents a quantum imaging method using undetected squeezed photons with enhanced brightness via an optical parametric oscillator, achieving high signal-to-noise ratio and noise-based image extraction for sensitive applications.

Contribution

It introduces a novel quantum imaging setup with homodyne detection and OPO, surpassing low gain approximation limits and enabling noise-based, non-disruptive imaging.

Findings

Higher signal-to-noise ratio in images and phase measurements

Effective background noise suppression protocol

Potential for non-invasive bio-imaging of living cells

Abstract

In this work a quantum imaging setup based on undetected squeezed photons is employed for metrological applications such as sensitive phase measurement and quantum imaging. In spite of the traditional quantum imaging with undetected photons, introduced by A. Zeilinger et. al, the proposed setup is equipped by a homodyne detection and also the brightness of the quantum light is enhanced by an optical parametric oscillator (OPO). Introducing OPO may be diminish the validity of the low gain approximation, so a theoretical approach beyond this approximation is introduced. Due to the resource of squeezing, the results reveal the higher amount of signal to noise ratio, as a measure of image quality and phase-measurement accuracy. Accordingly, an imaging protocol is introduced to suppress the background noises, effectively. Interestingly, This protocol provides a way to extract the image information which is encoded in the quantum fluctuation (noise). Therefore, non-disruptive imaging is achievable, which is noteworthy subject in the field of bio-imaging of sensitive and low damage threshold living cells.