Patent ID: 7483140

Claim:
A planar integrated surface plasmon resonance (SPR) sensor comprising: a substrate having a first side and a second side; an planar optical waveguide fabricated on a surface of the first side of the substrate, the optical waveguide having a first end and a second end; a wavelength tunable emitter on a same surface of the substrate coupled with the first end of the optical waveguide wherein the wavelength of the emitted light is varied to obtain a transmission spectrum of light which passes through a sensing region for detecting variations in a refractive index by monitoring a maximum absorption peak shift in a wavelength domain; at one single photodetector formed on the same surface of the substrate coupled with the second end of the optical waveguide for measuring a transmitted intensity of light exiting the second end of the planar optical waveguide; and at least one SPR sensor area formed on the first side of the substrate to couple with a section of the optical waveguide between the wavelength tunable laser and the one single photodetector, wherein the optical waveguide routes a light from the light source past the at least one SPR sensor area which evanescently penetrates the at least one SPR sensor area.