Berlin 2018 – wissenschaftliches Programm
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KFM: Fachverband Kristalline Festkörper und deren Mikrostruktur
KFM 5: Whispering Gallery Mode Resonators II
KFM 5.7: Vortrag
Montag, 12. März 2018, 17:30–17:50, EMH 025
WGM resonator technique for condensed matter characterization — Hanna Hlukhova1, Nataliia Naumova1, Alexander Barannik2, Alexey Gubin2, Irina Protsenko2, Nikolay Cherpak2, and •Svetlana Vitusevich1 — 1Bioelectronics (ICS-8), Forschungszentrum Juelich, 52425 Juelich, Germany — 2Usikov Institute for Radiophysics and Electronics, 61085 Kharkiv, Ukraine
WGM resonators represent a key technique in enabling material studies due to their high-quality resonant mode operation using evanescent electromagnetic fields. A very small perturbation introduced by a material under test results in a shift of resonant frequency and change in quality factor, thus reflecting the unique dielectric properties of the material. In this work, we present several developed resonators made of sapphire or quartz materials and discuss the advantages of fabricated measurement cells. WGM resonators of various geometries and materials were suggested in order to utilize the full potential of electromagnetic fields as a test wave interacting with materials, such as single-crystal Fe-pnictides and bioliquids. The resonators were studied using numerical modeling methods. Experimentally obtained quality factors are in good agreement with modeled values. It was also shown that the resonator enables the measurement of the complex permittivity of materials with an error of about 1 %. Microfluid channels combined with WGM resonators operated in the Ka band open up the possibility of contactless measurements for small volumes of biological liquids. This work is supported by DFG project: VI 456/3-1. N.N. greatly appreciates support from the Heinrich Hertz-Foundation.