Chiroptical spectrometer in the VIS-UV range

Chiroptical spectrometer in the VIS-UV range

Contact persons: Angelo Giglia, L. Pasquali, M. Malvezzi, S. Nannarone

The electromagnetic field emitted by a synchrotron bending magnet constitutes because of its stability, continuous spectrum and polarization characteristics a useful source for optical spectroscopy.

The ability to exploiting these aspects for spectroscopic purposes has been one of the guidelines of BEAR’s research activity.

In this framework an apparatus specifically intended  to the optical spectroscopic application with circular polarized light in the visible-vacuum UV range (MgF2 cut off) employing the light beam provided by the beamline BEAR at Elettra (Italy) is under commissioning.

The optical source is an supplementary output of the beamline, typically set up to provide horizontally polarized light impinging with its electric field at 45° with respect to the optical axis of a photoelastic modulator.

chiroptical_sketchBasically the apparatus features a polarizer (Rochon prism), a photoelastic modulator (Hind instruments), and analyser (Rohon prism) and  a suite of detectors (photomultiplier, diodes, electron multipliers) and it offers a number of optical configurations including mainly transmission and reflectivity (specular, theta-2theta and diffused) in circular polarized light.

Sample holder features six degrees of freedom, it permits the study of solid, thin films and liquid samples (cell for liquid).   

The apparatus addresses to the wide field of chiroroptical spectroscopy. It extends in the UV the optical range featured by laboratory apparatuses equipped with conventional sources.