Absolute frequency measurements, with up to 1×10<sup>−11</sup> level accuracies, are presented for 60 lines of the P and R branches for the ν<sub>1</sub>+ν<sub>3</sub> band of <sup>13</sup>C<sub>2</sub>H<sub>2</sub> at 1.5 μm (194 THz). The measurements were made using cavity-enhanced, diode-laser-based saturation spectroscopy. With one laser system stabilized to the P(16) line and a second laser system stabilized to the line whose frequency was to be determined, a Cr:YAG frequency comb was employed to accurately measure the tetrahertz level frequency intervals. The results are compared with recent work from other groups and indicate that these lines would form a basis for a high-quality atlas of reference frequencies for this region of the spectrum.
© 2006 Optical Society of America
Original Manuscript: October 5, 2005
Manuscript Accepted: November 10, 2005
Alan A. Madej, John E. Bernard, A. John Alcock, Andrzej Czajkowski, and Sergei Chepurov, "Accurate absolute frequencies of the ν1+ν3 band of 13C2H2 determined using an infrared mode-locked Cr:YAG laser frequency comb," J. Opt. Soc. Am. B 23, 741-749 (2006)