ISSN:
1089-7690
Source:
AIP Digital Archive
Topics:
Physics
,
Chemistry and Pharmacology
Notes:
We studied the vibration-induced dipole moment of methane by observing Stark-modulation spectra of the 2ν3 band centered at 1.66 μm. The spectral purity of an external cavity semiconductor laser and radiation density in a Fabry–Perot cavity absorption cell are sufficiently high to record sub-Doppler saturated absorption lines with a spectral resolution of 0.8 MHz. First-order Stark shifts of the E-type symmetry components in the P(2), Q(2), Q(4), Q(5), R(2), R(4), and R(5) transitions were measured, and the vibration-induced dipole moments for the v3=2 state were determined. Their values clearly demonstrate the Coriolis-induced dipole term, yielding [5.79(5)+0.440(18)×(2L−3)] mD for the JR level, where L is defined to be −(R+1), 0, and R for the R=J−1, J, and J+1 levels, R and J are rotational and total angular momentum quantum numbers, and numbers in parentheses are 90% confidence intervals in unit of the last digit. © 1996 American Institute of Physics.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.472737
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