High resolution waveguide terahertz time-domain spectroscopy

Terahertz time-domain spectroscopy accesses the frequency range between 100 GHz and 5 THz by using the coherent generation and detection based on femtosecond laser sources. On the way to obtain fingerprint absorption spectra of molecular solids, terahertz waveguides have proven to be a valuable tool to extend the results to narrow and high resolution linewidths of crystalline solids. We will discuss the development, properties and applications of terahertz waveguide geometries for spectroscopic applications, in particular high-resolution measurements using parallel-plate waveguides.