An international team of scientists reports in Nature Photonics on a novel technique for a high-brightness coherent and few-cycle duration source spanning 7 optical octaves from the UV to the THz.
Importance of Analytical Optical Methods
Analytical optical methods are crucial in modern society, facilitating rapid and secure substance identification within solids, liquids, or gases. These methods exploit the varied interaction of light with substances across the optical spectrum. For instance, the ultraviolet range accesses electronic transitions, while the terahertz detects molecular vibrations.
Application in Hyperspectral Spectroscopy
Over the years, numerous techniques have been developed to achieve hyperspectral spectroscopy and imaging, allowing scientists to observe the behavior of molecules when they fold, rotate, or vibrate. This understanding aids in the identification of cancer markers, greenhouse gases, pollutants, or harmful substances. These ultrasensitive techniques find practical application in food inspection, biochemical sensing, and even in cultural heritage preservation, facilitating the investigation of ancient object materials, paintings, or sculptures.
Challenges in Source Development
A persistent challenge has been the absence of compact sources covering a broad spectral range with sufficient brightness. While synchrotrons offer spectral coverage, they lack the temporal coherence of lasers and are typically only available in large-scale user facilities.
Recent Breakthrough in Source Development
Now, in a recent study published in Nature Photonics, an international team of researchers including OPTOlogic researchers from ICFO, the Max-Planck Institute for the Science of Light, the Kuban State University, and the Max-Born-Institute for Nonlinear Optics and Ultrafast Spectroscopy, led by ICREA Prof. at ICFO Jens Biegert, report on a compact high-brightness mid-IR-driven source combining a gas-filled anti-resonant-ring photonic crystal fiber with a novel nonlinear-crystal. The tabletop source provides a seven-octave coherent spectrum from 340 nm to 40,000 nm with spectral brightness 2-5 orders of magnitude higher than one of the brightest Synchrotron facilities.
Future Research Directions
Future research will leverage the few-cycle pulse duration of the source for the time-domain analysis of substances and materials. This will open new opportunities for multimodal measurement approaches in areas such as molecular spectroscopy, physical chemistry, and solid-state physics, among others.
Cited Article
Ugaitz Elu, Luke Maidment, Lenard Vamos, Francesco Tani, David Novoa, Michael H. Frosz, Valeriy Badikov, Dmitrii Badikov, Valentin Petrov, Philip St. J. Russell & Jens Biegert. Seven-octave high-brightness and carrier-envelope-phase-stable light source. Nature Photonics volume 15, pages277–280 (2021)
