Patent ID: 7184135

Claim:
A system for measuring the refractive index of at least one medium, comprising: a waveguide comprising at least one transducer formed by a blazed Bragg grating, in a part of the waveguide brought into contact with a medium, wherein the spectral response of the blazed Bragg grating depends on the refractive index of the medium by means of energy coupling between the guided mode and cladding modes and/or a continuum of radiative modes; a light source optically coupled to the waveguide in order to direct light therein and to make the light interact with the grating; spectral analysis means for analyzing the light which has interacted with the blazed Bragg grating and for providing a spectrum corresponding to the grating; acquisition means for recovering the spectrum; and electronic processing means for determining, from the spectrum thus recovered, a value of the refractive index of the medium.