Resolution of Quantum Imaging with Undetected Photons

TL;DR

This paper investigates the resolution limits of quantum imaging with undetected photons, revealing that the spatial resolution is governed by the momentum correlation between photons and can surpass the wavelength of detected light.

Contribution

It provides both theoretical and experimental insights into how momentum correlation influences resolution, demonstrating the potential for higher resolution imaging beyond traditional wavelength constraints.

Findings

Resolution is governed by momentum correlation between photons.

Stronger momentum correlation leads to higher resolution.

Resolution can be characterized by the wavelength of undetected light.

Abstract

Quantum imaging with undetected photons is a recently introduced technique that goes significantly beyond what was previously possible. In this technique, images are formed without detecting the light that interacted with the object that is imaged. Given this unique advantage over the existing imaging schemes, it is now of utmost importance to understand its resolution limits, in particular what governs the maximal achievable spatial resolution. We show both theoretically and experimentally that the momentum correlation between the detected and undetected photons governs the spatial resolution - a stronger correlation results in a higher resolution. In our experiment, the momentum correlation plays the dominating role in determining the resolution compared to the effect of diffraction. We find that the resolution is determined by the wavelength of the undetected light rather than the wavelength of the detected light. Our results thus show that it is in principle possible to obtain resolution characterized by a wavelength much shorter than the detected wavelength.