Patent ID: 8279427
Filing Date: 2012-10-02
Classification: G01N

Abstract:
1. A method for measuring the refractive index of a material with Bragg gratings, comprising an emission of a radiation from a radiation source, an interaction of the radiation with a Bragg grating, a spectral analysis of the radiation that interacted with the Bragg grating and a correlation of the spectral analysis with a value of the refractive index of the material to be examined, comprising the following steps: emitting a collimated radiation beam from a radiation source with a large spectrum and orientation thereof along a direction normal to the material to be examined; propagating the collimated radiation beam entering the material to be examined, then a Bragg diffraction grating that is obliquely placed to the direction of the collimated radiation beam, and again the material to be examined; subjecting to spectral analysis the collimated radiation beam exiting the material to be examined, the grating producing a minimum in the spectrum subjected to the spectral analysis in accordance with Bragg's law; and calculating the refractive index of the material to be examined from the measure of the wavelength corresponding to said minimum in the spectrum.