Methods and apparatus for vacuum ultraviolet (VUV) or shorter wavelength circular dichroism spectroscopy

摘要

A highly efficient vacuum ultraviolet circular dichroism spectrometer is provided; the spectrometer suitable for laboratory use or for integration into a beam line at a synchrotron radiation facility. In one embodiment, a spectroscopic circular dichroism instrument is provided; the instrument configured so as to enable circular dichroism data to be simultaneously obtained for multiple wavelengths of light. The instrument may be further configured to operate in at least a portion of the vacuum ultraviolet wavelength region.

主权项

1. A spectroscopic circular dichroism instrument, comprising:
a light source which generates a multi-wavelength light beam comprised of light of a plurality of wavelengths; a region of the spectroscopic circular dichroism instrument for the placement of a sample from which a circular dichroism measurement is to be obtained by exposure of a sample to the multi-wavelength light beam; a constant phase difference compensator optically coupled to the multi-wavelength light beam, the constant phase difference compensator introducing a phase difference between two orthogonal polarization components of the multi-wavelength light beam, the constant phase difference compensator being configured to be rotatable to allow rotation between the constant phase difference compensator and an optical axis of the multi-wavelength light beam; an optical element coupled to the multi-wavelength light beam, the optical element selecting a linearly polarized component of the multi-wavelength light beam; a detector coupled to the multi-wavelength light beam to provide a circular dichroism measurement of the sample, the instrument being capable of providing the circular dichroism measurement simultaneously for multiple wavelengths; and an optical path of the spectroscopic circular dichroism instrument, the optical path being configured to allow the multi-wavelength light beam to pass through the compensator and the optical element after exposure of the sample to the multi-wavelength light beam; wherein the spectroscopic circular dichroism instrument configuration is capable of allowing circular dichroism spectra to be extracted from dc and 2ω components of a detected intensity signal wherein ω is an angular frequency of the compensator rotation.