186 research outputs found
Experimental Determination of the 1 Sigma(+) State Electric-Dipole-Moment Function of Carbon Monoxide up to a Large Internuclear Separation
Experimental intensity information is combined with numerically obtained vibrational wave functions in a nonlinear least squares fitting procedure to obtain the ground electronic state electric-dipole-moment function of carbon monoxide valid in the range of nuclear oscillation (0.87 to 1.01 A) of about the V = 38th vibrational level. Mechanical anharmonicity intensity factors, H, are computed from this function for delta V + = 1, 2, 3, with or = to 38
Adaptive dual-comb spectroscopy in the green region
Dual-comb spectroscopy is extended to the visible spectral range with a
set-up based on two frequency-doubled femtosecond ytterbium-doped fiber lasers.
The dense rovibronic spectrum of iodine around 19240 cm-1 is recorded within 12
ms at Doppler-limited resolution with a simple scheme that only uses
free-running femtosecond lasers
Raman-induced Kerr-effect dual-comb spectroscopy
We report on the first demonstration of nonlinear dual-frequency-comb
spectroscopy. In multi-heterodyne femtosecond Raman-induced Kerr-effect
spectroscopy, the Raman gain resulting from the coherent excitation of
molecular vibrations by a spectrally-narrow pump is imprinted onto the
femtosecond laser frequency comb probe spectrum. The birefringence signal
induced by the nonlinear interaction of these beams and the sample is
heterodyned against a frequency comb local oscillator with a repetition
frequency slightly different from that of the comb probe. Such time-domain
interference provides multiplex access to the phase and amplitude Raman spectra
over a broad spectral bandwidth within a short measurement time. Experimental
demonstration, at a spectral resolution of 200 GHz, a measurement time of 293
{\mu}s and a sensitivity of 10^-6, is given on liquid samples exhibiting a C-H
stretch Raman shift.Comment: 7 pages, 4 figure
NEW YEAR INFRARED WAVENUMBER STANDARDS BY FOURIER SPECTROSCOPY IN VACUUM
D.H. Rank, A.H. Guenther, G.D. Saksena, J.N. Shearer and T.A. Wiggins, J. Opt. Soc. Am. 47, 8, 686 (1957). G. Guelachvili, Nouv. Rev. Optique Appliquee 3, 6, 317 (1972). G. Guelachvili, These ORSAY (1973). P. Heminger, F.C. De Lucia and W. Gordy, Phys. Rev. Lett. 25, 20, 1397 (1970).Author Institution: Laboratoire AIME COTTONThe 2 -- 0 band lines of , at about , are the most frequently used ones for the wavenumber calibration of near infrared spectrometers. The values of these wavenumbers, up to now considered as standards, have been given a long time ago by D.H. Rank and his co-workers The High Information Fourier Spectrometer, built at Laboratoire AIME COTTON, is now operating in and provides absolute wavenumber measurements. It has been used to measure the 2 - 0 band of which lines were directly referred, in the experiment, to the Krypton 86 Standard line at 16 . The estimated relative error on the lines position is . The relative precision is increased by 16 when compared with that of the previous standards. Comparison between the two sets of CO lines shows some discrepancies. The rotational leads, combined with the value given by P. Heminger leads to the following Velocity of Light km/s. The precision on the i.r. and the r.f. rotational constant values have the same order of magnitude
NEW DETERMINATION OF INFRARED WAVELENGTH STANDARDS BY VACUUM FOURIER SPECTROSCOPY
Author Institution: Laboratoire Aim\'{e} Cotton, C. N. R. S. IINew wavelength standards are obtained in the spectral region. They consist of lines belonging to the vibration-rotation spectra of , , CO molecules and some of their isotopic species. Their measurement has been performed with reference to the krypton - 84 Length Etalon by using 2-0 CO band lines previously determined on the same apparatus with an estimated relative error of 3 10
WAVELENGTH STANDARDS IN THE RANGE, DUNHAM COEFFICIENTS OF CO
New wavenumber standards are measured by F.T.S. in vacuum. lines extend from about 1100 to . Their accuracy is of the order of 50 to 150 . The water lines are obtained with a similar accuracy on a wider range. These data measured for the first time with a high information technique are located in a spectral area where experimental wavenumber references were up to now practically absent. They should be useful for accurate calibration of diode and Fourier spectra. An extensive work on CO covering a large domain of vibration and rotation quantum numbers in the fundamental electronic state , is reported
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