Application Of High-resolution Spectroscopy Research Articles

Standing-wave and intensity effects in intracavity laser RF double resonance spectroscopy

The laser and RF absorption spectra in a laser-RF double resonance configuration with the gas sample placed inside the laser cavity are exactly calculated by means of a semiclassical three-level model and interpreted through the dressed atom approach. Laser standing-wave effects and intensity effects are studied. Several kinds of nonlinear coherent phenomena are evidence. High-resolution spectroscopic applications are considered.

Applications of high resolution spectroscopy to the identification of far-infrared laser emission from optically pumped13CH3OH

High-resolution infrared (IR) and far infrared (FIR) Fourier transform absorption spectra have been employed to investigate assignments of FIR laser lines reported from optically-pumped13CH3OH. The spectroscopic measurements are used in conjunction with the reported IR pump and FIR laser frequencies to form closed combination loops for several systems, serving to confirm the assignments and in some cases to improve the accuracy of the FIR laser frequencies. Frequency predictions from combination differences are also presented for a number of potential new FIR laser lines.

The rotationally resolved electronic spectrum of indole in the gas phase

The high resolution ultraviolet fluorescence excitation spectrum of indole in a supersonic jet has been measured. It was possible to resolve the rotational structure with an experimental resolution of 180 MHz. The details of the technique employed to achieve this resolution in the ultraviolet are described. Analysis of the high resolution spectrum yielded a transition moment direction which is compared to previous theoretical predictions. Application of high resolution spectroscopy to the problem of distinguishing the 1La and 1Lb electronic states in indole and indole derivatives is discussed. From the measured rotational constants possible geometries for the ground and excited states were also determined.

Nonlinear saturated absorption in resonant media: Level-degeneracy-induced polarization effects

The effect of level degeneracy on saturated absorption in a resonant medium is considered using a simple but realistic three-level system to model $J=1\ensuremath{\rightarrow}J=0$ atomic transition. Assuming homogeneous broadening and exact resonance, an analytic nonperturbative expression for the medium susceptibility is obtained and used to study propagation of an arbitrarily polarized optical field. Optical saturation affects considerably Zeeman-coherence-induced circular dichroism. The analysis may find application in high-resolution spectroscopy and other branches of nonlinear optics.

TWO LASER RAMAN DIFFERENCE TECHNIQUE APPLIED TO HIGH PRECISION SPECTROSCOPY

Abstract : We have performed precision studies of stimulated resonance Raman transitions in an atomic beam and in a vapor. The extremely narrow resonances produced by such a scheme have applications in high resolution spectroscopy and in the development of new time and frequency standards. Our studies also provide fundamental information about the nature of atom-field interaction and can be compared directly with theoretical predictions.

Generation of high-spectral-brightness tunable XUV radiation at 83 nm

High-spectral-brightness coherent XUV radiation has been produced by third-harmonic generation of a transformlimited- bandwidth KrF* laser in gaseous xenon. The observed XUV output, which was continuously tunable from 82.8 to 83.3 nm, had a peak power of 40 mW, a bandwidth <0.01 cm(-1), and absolute frequency control to within 0.04 cm(-1). The utility of this XUV source for high-resolution spectroscopic applications is demonstrated by absorption studies in molecular hydrogen.

Evaluation of CF2Cl2 spectral parameters for atmospheric sensing

Laboratory infrared absorption spectral measurements of CF2Cl2 in the 10.8 μm band have been performed. Doppler limited resolution has been achieved using semiconductor tunable lasers. The line strength and the self and pressure broadening rates have been measured for the 918.562 and 918.621 cm−1 lines. The results are used for considerations on the application of high resolution spectroscopy to the measurement of atmospheric CF2Cl2.