Title :
Long path length cw-THz spectrometer using a multipass cell
Author :
Hindle, Francis ; Yang, Chun ; Cuisset, Arnaud ; Mouret, Gael ; Bocquet, Robin
Author_Institution :
Lab. de Physico-Chimie de l´´Atmos., Univ. du Littoral Cote d´´Opale, Dunkerque
Abstract :
Multipass cells have been extensively used in the infrared. Their use at THz frequencies is minimal due to the difficulty of coupling the highly divergent THz beams. The divergence of a cw-THz photomixing source was characterized and included in a beam propagation calculation to match the THz beam to a multipass cell. Path lengths up to 20 m have been realized. The spectra of carbonyl sulfide (OCS), vinyl chloride (CH2CHCl) and dimethyl sulfoxide (DMSO), (CH3)2SO are used to demonstrate the improved sensitivity of the spectrometer.
Keywords :
organic compounds; submillimetre wave propagation; terahertz wave spectra; THz beams; THz spectrometer; beam propagation; carbonyl sulfide; dimethyl sulfoxide; multipass cell; photomixing source; vinyl chloride; Apertures; Frequency measurement; Infrared spectra; Isotopes; Laser beams; Mirrors; Optical coupling; Samarium; Spectroscopy; Vibration measurement;
Conference_Titel :
Infrared, Millimeter and Terahertz Waves, 2008. IRMMW-THz 2008. 33rd International Conference on
Conference_Location :
Pasadena, CA
Print_ISBN :
978-1-4244-2119-0
Electronic_ISBN :
978-1-4244-2120-6
DOI :
10.1109/ICIMW.2008.4665738
