Linear and Circular Dichroism in the Vacuum Ultraviolet Region

Abstract

Circular dichroism spectroscopy has been extended to the VUV region through the introduction of the photo-elastic modulator with a calcium fluoride optical element. Spectroscopic and stereochemical applications of the technique to chiral molecules in the vapour and in the condensed phase are reviewed, together with related linear dichroism studies of orientated molecular systems

Polarization measurements for atomic and molecular emissions in the vacuum ultraviolet

“…Polarization measurements thus yield, in a very direct way, data on populations, coherence properties and, in special cases, the relative phases of the relevant amplitudes of excited states [3-71. The relation between the symmetry of atoms/molecules and their interaction with polarized radiation has also been used in absorption studies and that line of research has developed into the highly successful field of dichroism spectroscopy [Z, 61. Initially polarization spectroscopy studies were restricted mainly to the visible region of the spectrum but with the development of new detectors and new tunable sources of w and v w radiation (synchrotron radiation and frequency-doubled or mixed beams of dye lasers) interest has shifted in the last decade to these spectral regions, where fundamental excitation processes of targets like H, HI and noble gases [3-51 as well as chromophores, which display significant absorption only in the v w [2], can be studied.…”

“…Photon fluxes available in atomic physics experiments are typically of the order of 103-104 photons per second and single-photon counting is the method most commongly used for detection and analysis of the radiation. For this reason several techniques developed in the last two decades for polarization analysis of vw radiation, such as methods based on lock-in detection of modulated beams, cannot by employed in studies of such weak signals (see for instance analysis in [2]).…”

Design and construction of a compact end-station at NSRRC for circular-dichroism spectra in the vacuum-ultraviolet region

“…For this reason the PEM has become mainstream for measurement of vacuum-ultraviolet circular dichroism (VUVCD) (Schnepp et al, 1970;Johnson, 1971;Pysh, 1976;Drake & Mason, 1977). The history of the development of VUVCD is presented elsewhere (Drake & Mason, 1978, and references therein).…”