ISSN:
1432-0649
Keywords:
33.20
;
07.65.Gj
;
42.72
Source:
Springer Online Journal Archives 1860-2000
Topics:
Physics
Notes:
Abstract We present a very high-resolution heterodyne spectrometer based on a CO laser which operates down to fundamental-band transitions of the molecule. This allows us to detect saturated absorption signals on these transitions at very low pressure (0.4 Pa) and laser intensity (〈 1 mW/cm2), yielding a linewidth of about 250 kHz. With the CO fundamental-band laser stabilized to these saturation signals we have measured the transition frequencies of the fundamental bands of three isotopic species to an accuracy of typically 20 kHz (Δv/v ≈ 3 × 10−10), referenced to the CO2 frequency standard. Together with additional frequency measurements of the first hot bands, these provide the first heterodyne frequency data of sub-Doppler accuracy for transitions in low lying bands of CO. They now represent the most accurate secondary frequency standard in the spectral region around 5 µm (60 THz).
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01081166
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