title: Absolute frequency list of the ν3-band transitions of methane at a relative uncertainty level of 10(-11).
abstract: We determine the absolute frequencies of 56 rotation-vibration transitions of the ν(3) band of CH(4) from 88.2 to 90.5 THz with a typical uncertainty of 2 kHz corresponding to a relative uncertainty of 2.2 × 10(-11) over an average time of a few hundred seconds. Saturated absorption lines are observed using a difference-frequency-generation source and a cavity-enhanced absorption cell, and the transition frequencies are measured with a fiber-laser-based optical frequency comb referenced to a rubidium atomic clock linked to the international atomic time. The determined value of the P(7) F(2)((2)) line is consistent with the International Committee for Weights and Measures recommendation within the uncertainty.
authors: Department of Physics, Faculty of Science and Technology, Keio University, 3-14-1, Hiyoshi, Yokohama, 223-8522, Japan. s_works@a5.keio.jp
authors: Sho
authors: S
authors: Okubo
authors: Hirotaka
authors: H
authors: Nakayama
authors: Kana
authors: K
authors: Iwakuni
authors: Hajime
authors: H
authors: Inaba
authors: Hiroyuki
authors: H
authors: Sasada
mesh_terms: D004867:Equipment Design; D019544:Equipment Failure Analysis; D007834:Lasers; D008422:Materials Testing / Q000295:instrumentation*; D008697:Methane / Q000737:chemistry*; D008832:Microchemistry / Q000295:instrumentation*; D010783:Photometry / Q000295:instrumentation*
chemical_list: D008697:Methane