An international study involving Italian researchers of the Institute of Applied Sciences and Intelligent Systems of the National Research Council of Italy (Cnr) opens new oavenues for trapping and converting light energy.
An international collaboration involving Italian researchers of the Institute of Applied Sciences and Intelligent Systems of the National Research Council of Italy in Naples (Cnr-Isasi), US researchers from the Molecular Foundry in Berkeley, and scholars from the National University of Singapore (NUS) has achieved a significant breakthrough in the field of nanophotonics. This research area explores the behavior of light and its interaction with matter at the nanoscale.
Published on Nature, this study unveils a groundbreaking physical phenomenon known as “supercritical coupling.” This phenomenon enables the amplification of the efficiency in converting low-energy photons (invisible) into high-energy photons (visible) by several orders of magnitude. The implications of this discovery extend to diverse scientific domains, paving the way for innovative approaches in manipulating light. Furthermore, it holds the potential to drive progress in quantum technology, high-resolution imaging, and the development of photonic devices, including lasers, optical cavities, and resonators.
“The conversion of photons is a crucial technique with numerous applications, from light generation to super-resolution microscopy. To enhance the efficiency of this process, it is necessary to amplify the interaction between photons and atoms that trigger the conversion process: this is where the concept of supercritical coupling comes into play,” explains Gianluigi Zito (Cnr-Isasi), the study’s coordinator alongside Xiaogang Liu from the Department of Chemistry at the National University of Singapore. “We have exploited the physical property of so-called bound states in the continuum (BICs), whereby a photon can support a configuration of the electromagnetic field in which light, instead of propagating through space, remains ‘trapped’ without losing energy. In this way, we have demonstrated an eight-order-of-magnitude increase in light conversion, as well as the direct propagation of converted photons into visible light with exceptional precision.”
By trapping low-energy photons, they can engage in numerous interactions with the matter responsible for their conversion into visible photons, thereby harnessing and managing the phenomenon’s properties with heightened efficiency. This capability also facilitates the augmentation of other pertinent physical phenomena within cutting-edge technologies.
“This study, in addition to being a fundamental discovery, represents a true paradigm shift in the field of nanophotonics, altering our understanding of manipulating light at the nanoscale. The implications of supercritical coupling go beyond photon conversion and offer potential advancements in quantum photonics and various systems based on coupled resonators,” adds Xiaogang Liu (National University of Singapore).
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Gianluigi Zito, Cnr-Isasi gianluigi.zito@cnr.it
