Optical Spectroscopy of Novel Materials
The main topic of the research group of Andrei Pimenov (AP) is the broadband optical spectroscopy. From the point of view of the experimental technique the activities are centered on terahertz and millimeter-wave frequency regions. These spectral regions are available for only few experimentalists in the world because of the complexity of the apparatus and the necessity to carry out measurements on the border between the geometrical optics and the uniform-field-approximation. At present, reliable results on various complex systems can be done in presence of such external parameters like temperature, static electric and magnetic fields. Within the cooperation with the group of Karl Unterrainer it is planned to extend the experimental activities to the time resolution in the terahertz frequency range and to the pump-probe spectroscopy.
The central frequency region is being expanded both to low and high frequencies in order to be able to cover in total the range of 18 decades in frequency. This will finally be done as a combination of four spectrometers. One of them, for the microwave frequency range, will be available within the cooperation with the group of Silke Bühler-Paschen. Concerning the complex impedance experiments at radiowave frequencies the AP group will strongly benefit from the experience by the group of Jürgen Fleig. The spectrum of materials and systems investigated ranges from superconductors and topologically protected states up to metamaterials and magnetoelectrics.