Meta-materials; THz time domain spectroscopy; THz near-field imaging; Electron optics
Bagiante Salvatore, Enderli Florian, Fabianska Justyna, Sigg Hans, Feurer Thomas (2015), Giant Electric Field Enhancement in Split Ring Resonators Featuring Nanometer-Sized Gaps, in Scientific Reports
, 5, 1-5.
Brunner Fabian, Johnson Jeremy, Gruebel Sebastian, Ferrer Andres, Johnson Steve, Feurer Thomas (2014), Distortion-free enhancement of terahertz signals measured by electro-optic sampling. I. Theory, in JOSA B
, 31(4), 904-910.
Johnson Jeremy, Brunner Fabian, Gruebel Sebastian, Ferrer Andres, Johnson Steve, Feurer Thomas (2014), Distortion-free enhancement of terahertz signals measured by electro-optic sampling. II. Experiment, in JOSA B
, 31(5), 1035-1040.
Fabianska Justyna, Kassier Gunther, Feurer Thomas (2014), Split ring resonator based THz-driven electron streak camera featuring femtosecond resolution, in Scientific Reports
, 4, 1-6.
With the advent of meta-materials, which are mostly composed of sub-wavelength resonating structures, unprecedented electromagnetic material properties became accessible. These unusual properties are based on the microscopic electric and magnetic response of the constituting building blocks to an incident electromagnetic wave. Over the past years we have developed two complementary experimental techniques to measure the vector electric near-field distributions in the THz spectral range. With these techniques we have investigated the near-field distribution of several sub-wavelength structures (meta-materials), couplings between them, and couplings to lattice modes once they are arranged in periodic arrays. We found that, with slight modifications, these sub-wavelength structures can be used advantageously in two different fields, namely in THz spectroscopy and in electron optical devices.In THz spectroscopy, we want to make use of the giant field enhancement that comes hand in hand with introducing submicron-sized voids in these structures. Despite all efforts in THz near-field imaging it is impossible to measure the resulting field enhancement factors directly, which is why we propose different indirect methods to asses them. Further methods involve spatially resolved THz pulse transmission measurements and THz spectroscopic applications.We also want to demonstrate, through simulations mostly, that these sub-wavelength structures may find useful applications in electron trajectory manipulation. We propose a THz streak camera with possibly femtosecond time resolution based on a split ring resonator. Moreover, we propose a structure composed of several split ring resonators mimicking a THz-driven analogue of an undulator or a wiggler.