I will overview our results in sensing with one- and two-dimensional periodic arrays of nanostructured elements. To improve sensitivity we employed nonlocal resonances featured by guided-mode resonances or bound-state-in the continuum modes. We proposed two novel modifications of one-dimensional high-contrast gratings. Fabrication of the devices is done by deep-UV lithography, optimized etching and atomic layer deposition with conventional materials: silicon, alumina, titania and BCB polymer. Characterization of the sensors reveals improved sensing parameters, consistent with requirements for modern clinical diagnostic applications. 

In the second part, I will report about our progress in the Third Harmonic Generation (THG) in metasurfaces. In contrary to the standard approach of acquiring the enhanced THG at the zero-crossing point (epsilon-near-zero frequency), we found out numerically the best results for the minimal refractive index. We investigate numerically THG in patterned silicon-rich nitride membranes (metasurfaces) using the guided mode resonances for the enhancement of the nonlinear interactions. As the fundamental harmonic is set up for the laser wavelength of 800 nm, the third harmonic is reaching the UVC band. The result is expected to be confirmed experimentally.  

Andrei V. Lavrinenko received the Ph.D. and Doctor of Science degrees from the Belarusian State University (BSU) in Minsk, Belarus in 1989, and 2004, respectively. Since 2004, he has been an Associate Professor with the Department of Photonics Engineering, Technical University of Denmark (Kgs. Lyngby, Denmark). Since 2008, he has been leading the Metamaterials Group of the Department of Photonics Engineering. He is the author or co-author of more than 350 publications, including 10 textbooks and book chapters, and more than 100 papers in peer reviewed journals. He has given more than 25 invited talks at international conferences.