Sub-Doppler resolution Stark-modulation spectra of 20 transitions in the ν3 band of methane have been recorded using a difference-frequency-generation source referenced to an optical frequency comb with a frequency uncertainty of a few kilohertz. First-order Stark shifts in the vibrational excited (v3 1) and ground states have been measured separately in the presence of an electric field up to 31 kV/cm. The observed spectra have been analyzed, taking into account the mixing of the vibration–rotation wave functions due to high-order vibration–rotation interactions. The permanent electric dipole moment constants induced by the vibration, rotation, and Coriolis-type terms in the v3 1 state, and those induced by rotation in the vibrational ground state, are determined as Pvib −16.827 mDebye, Prot′ = 18.6(4) μDebye, PCor = 10.4(17) μDebye, and Prot″ = 24.47(12) μDebye.
|Number of pages||11|
|Journal||Journal of the Optical Society of America B: Optical Physics|
|Publication status||Published - 2017 Dec 1|
ASJC Scopus subject areas
- Statistical and Nonlinear Physics
- Atomic and Molecular Physics, and Optics