Esmaspäeval, 7. oktoobril 2019 kell 14.15 toimub Physicumis W.Ostwaldi 1 ruumis D312
Laserspektroskoopia ja kiletehnoloogia ühisseminar No 276
Esineb Dr. Glen Kelp
Research Fellow in Materials Science, Institute of Physics, University of Tartu
Dielectric metasurfaces for gas sensing
Dielektrilised metapinnad gaasisensorite valmistamiseks
Metasurfaces are 2-dimensional patterned surfaces designed to have extraordinary electromagnetic properties. In recent years, dielectric metasurfaces (DMS) have entered the spotlight as a substitute for plasmonic counterparts. Due to lower Ohmic losses in the materials, DMS can be tailored to have high quality factor (>100) spectral resonances  and enhanced local fields, enabling applications ranging from planar ultra-thin optical components to sensors at visible and infrared (IR) wavelengths. Additionally, DMS provide compatibility with current microelectronics fabrication methods. The sharpness of spectral features of DMS is well suited for targeting the mid-IR vibrational lines of gases to detect the presence of molecules and their concentration. High localized field enhancement of metasurfaces is also known and has been experimentally exploited in biomolecule sensing . Although, so far little work has been done to realize DMS as gas sensors.
In this talk I will introduce the usage of DMS for gas sensing and my own upcoming research activities in this field. My research goal is to experimentally demonstrate a mid-IR spectroscopic gas sensing device based on DMS. High sensitivity gas sensor will be designed and constructed that responds to the characteristic mid-IR molecular vibrations of gases. The required sub-wavelength size nano-structures on IR transparent substrates will be fabricated using state of the art techniques: electron beam lithography and atomic layer deposited dielectrics.
 C Wu, N Arju, G Kelp, … Spectrally selective chiral silicon metasurfaces based on infrared Fano resonances, Nat Commun 2014
 A. Tittl, et al. Imaging-based molecular barcoding with pixelated dielectric metasurfaces. Science 2018
PS For postgraduate students: Seminar belongs to the Programme of Doctoral seminars LOFY.00.004 and by visiting it you can earn credit points!