Terahertz Quantum Imaging

TL;DR

This paper demonstrates a novel quantum imaging technique that captures terahertz spectral information using visible light detection, enabling high-resolution imaging without specialized terahertz cameras.

Contribution

The authors introduce a method for terahertz quantum imaging using undetected photons and quantum distillation, extending quantum imaging to challenging spectral regions.

Findings

Successful terahertz amplitude and phase imaging with visible photons

Achieved near-wavelength spatial resolution without cooling

Method aligns well with numerical simulations

Abstract

Quantum imaging with undetected photons spatially transfers amplitude and phase information from one spectral region of physical interest to another spectral region that is easy to detect. The photon energy of the two spectral regions can, in principle, be separated by several orders of magnitude. However, quantum imaging with undetected photons has so far only been demonstrated in spectral regions of similar order of magnitude in frequency (and for which cameras are commercially available). Here, we demonstrate amplitude- and phase-sensitive imaging in the terahertz spectral region (1.5 THz center frequency) by detecting only visible photons (center wavelength 662.2 nm, 452.7 THz center frequency) more than two orders of magnitude apart. As a result, terahertz spectral information can be reliably detected with a standard CMOS camera without cooling, achieving a spatial resolution close to the wavelength. By taking advantage of quantum distillation in a nonlinear interferometer, the influence of ubiquitous thermal terahertz photons can be neglected. Our results are in good agreement with numerical simulations of the imaging process and demonstrate the huge potential of this method to address otherwise challenging spectral regions where cameras do not exist.