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Updated: Jun 26, 2026

Characterizing Far-infrared Laser Emissions and the Measurement of Their Frequencies
Published on: December 18, 2015
Doppler-free spectroscopy of molecular iodine using a frequency-stable light source at 578 nm
Feng-Lei Hong1, Hajime Inaba, Kazumoto Hosaka
1National Metrology Institute of Japan (NMIJ), National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 3, Ibaraki, Japan. f.hong@aist.go.jp
Abstract:
A stable light source obtained using sum-frequency generation (SFG) is developed for high-resolution spectroscopy at 578 nm. Hyperfine transitions of molecular iodine are observed by using the SFG light source with saturation spectroscopy. The light source is frequency stabilized to the observed hyperfine transition and achieves a stability of 2x10(-12) for a 1-s averaging time. The absolute frequency of the light source stabilized on the a1 component of the R(37)16-1 transition is determined as 518304551833 (2) kHz. This transition serves as a frequency reference for the (1)S(0)-(3)P(0) optical clock transition in neutral ytterbium (Yb).
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