Terahertz time-domain spectroscopy in physics, chemistry, and biology

In the recent years there has been a tremendous increasing interest in the far-infrared, or THz spectral region. The field of THz photonics has broadened its scope from source- and detector development into application areas in a wide range of scientific disciplines. Today researchers and companies are investigating a wide range of applications of THz spectroscopy in medicine, gene analysis, safety and security, and pharmacy. In this presentation I will give an overview of THz research conducted in the recent years at the University of Freiburg. We have investigated fundamental interactions in ionic and molecular crystals, with special emphasis on transient carrier dynamics and phonon interactions. The latter has formed the basis of the field of chemical recognition based on fingerprint spectra of molecular systems in the THz range. I will finally give an outlook to what the near future holds for THz photonics, especially in terms of integrated THz photonics at the Technical University of Denmark.