@InProceedings{Schwaab_etal1999, author="Schwaab, G. W. and H{\"u}bers, H-W and Schubert, J. and Erichsen, Patrik and Gol{\textquoteright}tsman, G. and Semenov, A. and Verevkin, A. and Cherednichenko, S. and Gershenzon, E.", title="A high resolution spectrometer for the investigation of molecular structures in the THZ range", booktitle="Proc. 10$^{th}$ Int. Symp. Space Terahertz Technol.", year="1999", pages="530--538", optkeywords="antireflection coatings; dielectric mirrors", abstract="A status report on the design study of a novel tunable far-infrared (TuFTR) spectrometer for the investigation of the structure of weakly bound molecular complexes is given. The goal is a sensitive TuFIR spectrometer with full frequency coverage from 1-6 THz. To hit the goal, advanced sources (e.g. p-Ge lasers) and detectors (e.g. superconducting hot electron bolometric (HEB) mixers) shall be employed to extend the technique of cavity ringdown spectroscopy, that is currently used at optical and infrared frequencies to the FIR spectral range. Critical for such a system are high-Q resonators that still allow good optical coupling, and wideband antireflection coatings to increase detector sensitivity and decrease optical path losses. 2 nd order effective media theory and an iterative multilayer algorithm have been employed to design wideband antireflection coatings for dielectrics with large dielectric constants like Ge or Si. Taking into account 6 layers, for Si bandwidths of 100{\%} of the center frequency could be obtained with power reflectivities below 1{\%} for both polarizations simultaneously. Wideband dielectric mirrors including absorption losses were also studied yielding a bandwidth of about 50{\%} with reflectivities larger than 99.5{\%}.", optnote="exported from refbase (https://db.rplab.ru/refbase/show.php?record=1577), last updated on Tue, 25 May 2021 14:44:29 -0500", opturl="https://www.nrao.edu/meetings/isstt/1999.shtml" }