Researchers from the International Iberian Nanotechnology Laboratory (INL), the LEARN project’s coordinator, have published a new paper in the Optics Letters journal reporting, for the first time, that the excitation of optical anapoles states can be achieved at the UV-A wavelength range.
The article, entitled ‘Optical anapoles excited by UV-A illumination‘, was developed in the Diéguez group under the scientific leadership of Pieter De Beule.
This research means a step forward for the LEARN project’s Work Package 4, devoted to the development of novel sensors to detect Ultrafine Particles (UFPs) and Volatile Organic Compounds (VOCs) in the air.
INL is investigating the possible designs for a multiwavelength third harmonic generation with a single nanostructure, to be integrated into the prototype and validated experimentally for increased photoionisation generation from VOCs.
The photoionisation of VOCs through Vacuum UltraViolet light
INL’s work in this regard focuses on the photoionisation of VOCs through Vacuum UltraViolet (VUV) light (100-200nm), that has corresponding photon energies high enough to photoionise molecules. Part of that consists of the consideration of new material structures that can significantly enhance the creation of VUV through specifically designed nanostructured materials.
In this article, INL reports theoretically, for the first time, that they can have the excitation of optical anapoles states at the UV-A wavelength range. Anapoles refer to a condition whereby light scattering from an object is reduced to a minimum and concomitantly the local electric field inside nanostructures is highly increased.
These strong electric fields lead to a significant increase in third harmonic generation efficiency, and henceforth also in the improved generation of VUV by THG pump wavelengths corresponding to 315-400 nm. The VUV photon energies achievable with this arrangement span 9.1-11.8 eV, ideal for achieving VOC photoionisation.
Source: Diogo Poeta, Rafael Vilarinho, Martín López-García, and Pieter A. A. De Beule, “Optical anapoles excited by UV-A illumination,” Opt. Lett. 49, 7198-7201 (2024). https://doi.org/10.1364/OL.536925
The LEARN project is a Horizon Europe project meant to monitor and evaluate indoor air quality at schools around Europe and its impact on children’s health. Our main goal is to develop and deploy novel sensors that can detect possibly harmful air pollutants, as well as advanced biosensors and optimised air remediation strategies. Find out more about our EU-funded project!
