Patent ID: 8773662
Filing Date: 2014-07-08
Classification: G01N

Abstract:
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; an optical element coupled to the multi-wavelength light beam, the optical element selecting a linearly polarized component of the multi-wavelength light beam; and 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, wherein the compensator is rotatable, wherein circular dichroism spectra and linear dichroism spectra are extracted from a detected intensity signal, and wherein circular dichroism spectra are extracted from dc and 2ω components of the detected intensity signal and linear dichroism spectra are extracted from the dc and 4ω components of the detected intensity signal, wherein ω is an angular frequency of the compensator rotation.