You will use a tunable diode laser to carry out spectroscopic studies of the rubidium atom. You will measure the Doppler-broadened absorption profiles of the D2 transitions at 780 nm and then use the technique of saturated absorption spectroscopy to improve the resolution beyond the Doppler limit and measure the nuclear hyperfine splittings, which are less than 1 ppm of the wavelength. A FabryP...

continued on page 4 continued on page 4 Theodor Hänsch makes a time measurement. Introduction Absorption spectroscopy is one of the oldest scientific methods for studying atomic and molecular structure. It is also one of the most powerful research tools for providing information about the world around us. One important application is ultrasensitive trace gas analysis, which is used in many area...

Ultraviolet Visible Near-Infra red (UV-Vis-NIR) spectroscopy is useful to characterize the absorption, transmission, and reflectivity of a variety of technologically important materials, such as pigments, coatings, windows, and filters. This more qualitative application usually requires recording at least a portion of the spectrum for characterization of the optical or electronic properties of ...

X-ray absorptioń spectroscopy, today widely used as a tool for structural investigations, is described. Theoretically it is shown that above an absorption edge the absorption coefficient is well approximated by a sum of terms, each one describing a particular path followed by the photoelectron outgoing from the atom. Such geometrical feature allows to use X-ray absorption spectroscopy for struc...

An original scheme for sensitive absorption measurements, particularly well-suited for low analyte concentrations, is presented. The technique is based on multiscattering-enhanced absorption spectroscopy (MEAS) and benefits from the advantages of conventional absorption spectroscopy: simplicity, rapidity, and low costs. The technique relies on extending the optical path through the sensing volu...

Resonant annihilation of extremely high-energy cosmic neutrinos on big-bang relic anti-neutrinos (and vice versa) into Z-bosons leads to sizable absorption dips in the neutrino flux to be observed at Earth. The high-energy edges of these dips are fixed, via the resonance energies, by the neutrino masses alone. Their depths are determined by the cosmic neutrino background density, by the cosmolo...

1.59.1 PHYSICS OF X-RAY ABSORPTION 1 1.59.1.1 X-ray Absorption Edges 2 1.59.1.2 X-ray Fluorescence 3 1.59.1.3 Measurement of X-ray Absorption Spectra 3 1.59.2 EXTENDED X-RAY ABSORPTION FINE STRUCTURE 6 1.59.2.1 Theoretical Description of EXAFS Spectra 6 1.59.2.1.1 Single scattering 6 1.59.2.1.2 Multiple scattering 8 1.59.2.1.3 Other corrections to the EXAFS equation 9 1.59.2.2 Programs for Calc...

X-ray spectroscopy studies of potassium intercalated metal-free phthalocyanine multilayers adsorbed on Al(110) have been undertaken. Photoelectron spectroscopy measurements show the presence of several charge states of the molecules upon K intercalation, due to a charge transfer from the alkali. In addition, the comparison of valence band photoemission spectra with the density functional theory...

The signal-to-noise ratio (SNR) in off-axis integrated cavity output spectroscopy (OA-ICOS) is investigated and compared to direct absorption spectroscopy using multipass absorption cells [tunable diode laser absorption spectroscopy (TDLAS)]. Applying measured noise characteristics of a near-IR tunable diode laser and detector, it is shown that the optimum SNR is not generally reached at the hi...