Fast quantum ghost microscopy in the mid-infrared
Individual photons and photon pairs shed light on molecular fingerprints
While we typically do not think of atoms in a molecule as moving around, molecules can stretch along their bonds, vibrate around their centres of mass and rotate around their axes. The frequencies (or corresponding wavelengths) at which these motions occur are characteristic and unique for each molecule, creating what is known as a spectral fingerprint. The molecular fingerprint region of the electromagnetic spectrum (the mid-infrared, or mid-IR region) is of tremendous interest because it provides a non-invasive way to identify and quantify molecules. The EU-funded FastGhost project is manipulating single photons and photon pairs to deliver a ground-breaking quantum imaging system for the mid-IR region targeting the medical sciences.
Quantum imaging using non-classically correlated photon pairs has been shown to possess a number of fundamental advantages with respect to known imaging modalities based on classical light. These are the possibilities to image with very low photon number while maintaining a high image quality, to have sample interaction and spatial detection on different wavelength channels. Although these advantages signify a large potential for applications, realizations so far only have been on the level of principle demonstrations. The overarching goal of the FastGhost project is to move quantum imaging from a conceptually demonstrated experimental approach to a technology with viable benefits for applications.The strongly linked FastGhost consortium will demonstrate the benefits of quantum imaging in a microscopy lab demonstrator on TRL 4, which will perform measurements with high spatial resolution in the mid-infrared spectral range while employing only spatially resolving detectors for visible light. To this end, photon pair sources optimized for quantum imaging, single-photon detectors for the mid-infrared, and highly resolving single-photon cameras will be developed in the project. The final demonstrator integrates all components and will represent a practically usable imaging device with application-oriented performance parameters. We will show the capabilities of the demonstrator in prototype applications that are targeting imaging in medicine and life sciences. This will enable quantitative assessment of the quantum advantages which will be used to identify marketable application cases.