January 2024 – June 2027
Projet ANR-23-CE47-0005 (ANR)
INTERQUO will provide THz sources ready to be used in highly sensitive coherent detection schemes, competitive with actual available resources, such as time domain spectroscopy.
Context
Terahertz (THz) covers the electromagnetic spectrum between infrared and microwaves. Owing to its capacity for unique bio-chemical specificity, THz holds strong promise for a wide range of applications in material analysis, environmental sensing, and health diagnostics. THz impacted high bandwidth free space communication since atmospheric windows fall in this spectrum and scattering by fog and pollution is reduced at long wavelengths. New horizons are expected to be opened in these fields when moving from classical to quantum sources. THz applications rely on detectors with limited performances, intrinsically limited by the energy of the photon to be measured that is comparable to the one of the thermal environmental background. Quantum mechanics provides a powerful tool to overcome these limitations: the entanglement.
INTERQUO will demonstrate highly sensitive THz detection in spectroscopy and imaging application based on quantum protocols. By linking a THz photon (a few meV) to another one at higher energy (~1.6 eV), THz interaction with matter is accessible by detection performed solely on highly sensitive detectors in the Near-Infrared (NIR). This scheme of undetected photons is not affected by the thermal radiation background, relying on the quantum correlation between two photons in an entangled pair. INTERQUO will demonstrate miniaturized THz sources based on Gallium Phosphide (GaP), a material with an intrinsic dispersion extremely well adapted to the generation of THz-NIR photon pairs by nonlinear interactions. GaP is compatible with silicon technology, making THz quantum source ready to be used in established photonic circuits. High brightness THz sources will be demonstrated in waveguide designed GaP chips, where the overlap among the modes involved in the nonlinear process is optimized at the same time of the outcoupling of the light out of the semiconductor structures.
Goals
INTERQUO will provide THz sources ready to be used in highly sensitive coherent detection schemes, competitive with actual available resources, such as time domain spectroscopy. INTERQUO will cover the high THz (20 to 35 THz) and the low THz ranges (1 to 6 THz), where classical techniques for coherent spectroscopy demand relative costly infrastructures, such as ultrafast lasers and amplifiers, as well as complex detection technologies.
In this project we will demonstrate THz coherent detection demanding well established semiconductor technologies, continuous wave lasers and NIR single photon detectors. At the same INTERQUO will overcome the use of THz cameras, costly detector with limited number of pixels and poor performance, for imaging application. THz is a powerful tool in biology and medical applications as a non-invasive probe to discriminate healthy from sick tissue and to observe cells without induction of photochemical effect. However, the lack of highly sensitive detectors in the THz causes the use of strong pulses for imaging applications that can induce strong alteration of biomolecules such as DNA instabilities or shock-waves. INTERQUO provides a solution, highly sensitive THz imaging will be available on NIR cameras. At the same time, fundamental tests of quantum mechanics, routinely performed for quantum information processing, will be accessible in the THz spectrum, paving the way towards wider application of THz in quantum physics.
Scientific production
Documents récupérés de l'archive ouverte HAL 
Partners
MPQ (Paris), Inst. FOTON (Rennes), C2N (Saclay), LPENS (Paris).
Coordinator
Maria AMANTI (MPQ)
Coordinator iFOTON: Alexandre BECK (Foton-OHM)
Fundings
ANR (589 k€)
See online
