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Author Bethardy, G. A. ♦ Perry, D. S.
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword PHYSICS ♦ MOLECULES ♦ ABSORPTION SPECTROSCOPY ♦ FREQUENCY MODULATION ♦ LASER RADIATION ♦ JETS ♦ ACETYLENE ♦ RESOLUTION
Abstract A device for high-resolution frequency-modulated absorption spectroscopy of jet-cooled molecules is described and demonstrated. Direct absorption spectra of jet-cooled molecules are recorded by multipassing an infrared laser beam through a free-jet expansion with all light rays perpendicular to the nozzle axis. In sliced-jet spectroscopy sub-Doppler resolution is obtained by inserting a small blade upstream from the laser crossing to obstruct molecules that would otherwise absorb at the center of the Doppler profile. Here the sliced-jet technique is extended by replacing the blade by a stainless-steel string vibrating at a frequency of about 10 kHz. Phase sensitive detection of the frequency-modulated absorption signal is accomplished with a lock-in amplifier. A resolution of 12 MHz is demonstrated using the modulated sliced-jet technique.
ISSN 00346748
Educational Use Research
Learning Resource Type Article
Publisher Date 1995-04-01
Publisher Place United States
Journal Review of Scientific Instruments
Volume Number 66
Issue Number 4


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