A novel design of a rf afterglow source of the oxygen forbidden lines at 630.0 and 557.7 nm for use in thermospheric dynamics studies is presented. With a repetitive discharge-afterglow excitation cycle, the source yields adequate afterglow intensities of the OI lines that are sufficiently free of background continuum for use in Fabry-Perot interferometer measurements of spectral line profiles. These lines provide accurate zero-velocity references in Fabry-Perot determinations of Doppler shifts in the OI thermospheric lines. The design considerations for the rf source are described, together with its preparation and filling by an ultrahigh-vacuum gas-handling system. Examples are given of the source’s output spectrum, as measured by a grating spectrometer, and its spectral line profiles, as determined by a Fabry-Perot interferometer. Comparative interferometry between the OI afterglow source lines and nearby (within ~0.01–0.02-nm) lines from hollow-cathode sources illustrates the means of establishing secondary reference sources in cases in which the primary OI afterglow source is not available.
© 2002 Optical Society of America
(120.2230) Instrumentation, measurement, and metrology : Fabry-Perot
(120.3180) Instrumentation, measurement, and metrology : Interferometry
(300.2140) Spectroscopy : Emission
(300.6210) Spectroscopy : Spectroscopy, atomic
(300.6320) Spectroscopy : Spectroscopy, high-resolution
Manfred A. Biondi, "Oxygen 630.0- and 557.7-nm Line Source for Thermospheric Dynamics Studies," Appl. Opt. 41, 6499-6506 (2002)