sub-doppler spectroscopy

Sub-Doppler tunable far-infrared spectroscopy.

The first experimental observations to our knowledge of sub-Doppler linewidths in a cell made using tunable far-infrared radiation are reported. A double-resonance scheme has been used, combining CO(2)-laser infrared radiation with tunable far-infrared radiation to observe a sub-Doppler line shape in an excited vibrational state of CH(3)OH.

Sub-Doppler mid-infrared spectroscopy of molecular ions

The technique of velocity modulation spectroscopy has recently been combined with cavity enhancement and frequency modulation methods into a technique called noise-immune cavity-enhanced optical heterodyne velocity modulation spectroscopy (NICE-OHVMS). We have implemented NICE-OHVMS with a cw-optical parametric oscillator (OPO) tunable from 3.2 to 3.9 lm, and used it to record spectra of the R(...

Multiplexed sub-Doppler spectroscopy with an optical frequency comb.

An optical frequency comb generated with an electro-optic phase modulator and a chirped radiofrequency waveform is used to perform pump-probe spectroscopy on the D1 and D2 transitions of atomic potassium at 770.1 nm and 766.7 nm, respectively. With a comb tooth spacing of 200 kHz and an optical bandwidth of 2 GHz the hyperfine transitions can be simultaneously observed. Interferograms are recor...

Cavity ring-down spectroscopy measurements of sub-Doppler hyperfine structure

D. A. Long,1 D. K. Havey,2 M. Okumura,1 C. E. Miller,3 and J. T. Hodges2 1Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, USA 2Process Measurements Division, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899, USA 3Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Gr...

Doppler-Free Saturation Spectroscopy

Communication: High precision sub-Doppler infrared spectroscopy of the HeH⁺ ion.

The hydrohelium cation, HeH(+), serves as an important benchmark for ab initio calculations that take into account non-adiabatic, relativistic, and quantum electrodynamic effects. Such calculations are capable of predicting molecular transitions to an accuracy of ~300 MHz or less. However, in order to continue to push the boundaries on these calculations, new measurements of these transitions a...