Patent ID: 9194798
Filing Date: 2015-11-24
Classification: G01N

Abstract:
1. A refractometer for multi-wavelength measurement of refractive index of a sample, comprising: a dispersive optical system comprising a diffraction grating configured to spectrally spread an optical beam that includes a range of wavelengths by imposing a wavelength dependent angular dispersion along a first axis and a first cylindrical lens configured to collimate the spectrally spread optical beam along the first axis to produce a collimated spectrally spread optical beam; and a focusing optical system configured to direct the collimated spectrally spread optical beam to be incident on an interface between the sample and a prism at a range of angles of incidence including a critical angle and further configured to focus the collimated spectrally spread optical beam along a second axis substantially perpendicular to the first axis so as to establish the range of angles of incidence and to produce a linear illumination pattern at the interface, wherein the linear illumination pattern is substantially parallel to the first axis and the wavelength of light of the linear illumination pattern varies as a function of distance along the first axis.