Laboratory of Near Field Optics
Michal Kvapil is involved in studies of optical properties of plasmonic antennas. After his master’s study, when he had been focused on numerical calculations of resonant properties of plasmonic antennas by finite-difference time-domain (FDTD) method, he switched to experimental part of the field. Currently, he is specialized on fabrication of plasmonic structures by electron beam lithography (EBL) on various substrates (e.g. Si, nanocrystalline diamond, SiO2, CaF2) mostly for the near- and mid-infrared part of the spectrum. For the analysis of optical response of fabricated structures he mainly uses the Fourier transform infrared spectroscopy (FTIR). He has also experiences with optical spectroscopy in visible range, Raman spectroscopy and functionalization of plasmonic structures.
Fig.: Numerical simulation (a,d), analytical calculation (b,e), and experimental SNOM image (c,f) of the near-field surface-plasmon-polariton interference pattern established over the squarelike structure (slits in 200-nm-thick Au film on quartz) being illuminated homogeneously by laser beam (633 nm) polarized in the direction indicated by white double arrow. Scale bars are 1 μm long.
Petr Dvořák has been involved in experimental studies of optical response of plasmonic nanostructures for last several years. For the analysis of the optical response he uses the aperture scanning near-field optical microscope (a-SNOM) and the confocal optical microscope operated in transmission or reflection mode in both dark and bright fields. The most frequently used method how he fabricates these plasmonic nanostructures is the top-down manufacturing consisting of two steps: (A) Depositing of ultrathin metal layers (e.g. Au, Ag, Cu, Al) in ultra high vacuum by ion beam sputtering (IBS) or ion beam assisted deposition (IBAD); (B) Selective removal of unwanted material by electron beam lithography (EBL) or focused ion beam (FIB).
Filip Ligmajer is within the frame of his Ph.D. project focused on the self-assembly of metallic nanoparticles and measurements of their optical properties. The tools for his reasearch are SEM/FIB system, dark-field spectroscopy and spectroscopic ellipsometry. He is also participating in the joint research with Institute of Biophysics ASCR focused on bio-detection.