Mid-Infrared Microscopy via Position Correlations of Undetected Photons

TL;DR

This paper introduces a novel mid-infrared microscopy technique using position correlations of undetected photons, achieving high resolution imaging below 10 micrometers and demonstrating potential biomedical applications.

Contribution

It is the first to utilize position correlations in quantum imaging with undetected photons, expanding the technique's capabilities beyond momentum correlations.

Findings

Achieved sub-10 μm resolution at 3.7 μm wavelength.

Successfully imaged mouse heart tissue at mid-IR.

Demonstrated potential for biomedical and industrial imaging.

Abstract

Quantum imaging with undetected photons (QIUP) has recently emerged as a new powerful imaging tool. Exploiting the spatial entanglement of photon pairs, it allows decoupling of the sensing and detection wavelengths, facilitating imaging in otherwise challenging spectral regions with mature silicon-based detection technology. All existing implementations of QIUP have so far utilised the momentum correlations within the biphoton state. Here, for the first time, we implement and examine theoretically and numerically the complementary scenario - utilising the tight position correlations formed within photon pair at birth. This image plane arrangement facilitates high resolution imaging with comparative experimental ease, and we experimentally show resolutions below 10 $\mu$m at a sensing wavelength of 3.7 $\mu$m. Moreover, imaging a slice of mouse heart tissue at the mid-IR to reveal morphological features on the cellular level, we further demonstrate the viability of the technique for the life sciences. These results offer new perspectives on the capabilities of QIUP for label-free wide-field microscopy, enabling new real-world applications in biomedical as well as industrial imaging at inaccessible wavelengths.