Patent ID: 8174698

Claim:
An integrated microfluidic refractometer for measuring a refractive index of a fluid, the refractometer comprising: a Fabry-Perot cavity having layers of silicon vertically through a plane of a substrate, the Fabry-Perot cavity comprising two reflectors each comprising three layers of silicon, wherein, in each reflector, a first layer of air is disposed between a first and a second of the layers of silicon and a second layer of air is disposed between the second and a third of the layers of silicon; and a microfluidic channel, horizontally formed in the plane of the substrate and connected to the Fabry-Perot cavity, for carrying the fluid to the Fabry-Perot cavity, wherein the microfluidic channel and the Fabry-Perot cavity are coplanar within the substrate; wherein the Fabry-Perot cavity detects a shift of wavelength corresponding to a variation of the refractive index when the fluid passes through the Fabry-Perot cavity.