Quantum Sensing with Extreme Light

Abstract

Optical nonlinear conversion processes are ubiquitously applied to scientific as well as industrial tasks. In particular, nonlinear processes are employed to generate radiation in many frequency ranges. In plenty of these nonlinear processes, the generation of paired photons occurs -the so-called signal and idler photons. Although this type of generation has undergone a tremendous development over the last decades, either the generated signal or the idler radiation has been used experimentally. In contrast, novel quantum-based measurement principles enable the usage of both partners of the generated photon pairs based on their correlation. These measurement approaches have an enormous potential for future applications, as they allow to transfer information from one spectral range to another. In particular, spectral ranges where photon generation and detection is particularly challenging can benefit from this principle. Above all, these include the extreme frequency ranges, such as on the low-frequency side the mid to far infrared or even the terahertz spectral range, but also on the high-frequency side the ultraviolet or X-ray spectral range. In this review article, theoretical and experimental developments based on correlated biphotons are described specifically for the extreme spectral regions.

Nonlinear Interferometry: A New Approach for Imaging and Sensing

“…In going beyond classical electrodynamics, new imaging and sensing features become possible. [4,5] As already experimentally demonstrated, non-classical states of light allow for super-resolution imaging, [6,7] sub-shot-noise sensing, [8,9] and super-sensitive Fluorescence detection. [10,11] In addition, a very promising method based on nonlinear interferometers allows to illuminate a sample with light that remains undetected, while the object's image is obtained with light that does not interact with it.…”

General Simulation Method for Quantum‐Sensing Systems

“…This distinctive feature of QIUL allows for a probing wavelength at which detection is difficult, while detecting the image at a convenient wavelength. [ 21 ]…”

“…This distinctive feature of QIUL allows for a probing wavelength at which detection is difficult, while detecting the image at a convenient wavelength. [21] Some properties of QIUL have been analyzed analytically and numerically. [9,10,[22][23][24] However, each work investigated only isolated aspects of QIUL, while a holistic description considering the interplay of various effects is still missing to date.…”