Patent ID: 9678004
Date: 2017-06-13
CPC Classifications: B82Y,G01N,G02B

Claim:
1. A plasmonic interferometer sensor comprising: a transparent substrate; and a conductive layer disposed on an upper surface of the transparent substrate, the conductive layer defining at least one circular groove extending inwardly partially through the conductive layer and in a direction towards the transparent substrate from the upper surface of the conductive layer and a circular central aperture extending entirely through the conductive layer to the transparent substrate such that the upper surface of the transparent substrate is exposed, wherein the at least one groove forms a concentric ring around the central aperture; the central aperture spaced apart by a distance from the at least one concentric groove along the upper surface of the conductive layer, wherein an interface between the upper surface of the conductive layer and an ambient medium defines a sensing surface between the at least one groove and central aperture; the sensing surface defining a first optical branch along which surface plasmon polariton modes are excited in response to at least partially coherent light at illumination wavelengths being received by the upper surface of the conductive layer, wherein surface plasmon polaritons travel from the at least one groove to the aperture along the sensing surface; a second optical branch formed by the light traveling from the ambient medium directly into the aperture; wherein the surface plasmon polaritons from the first optical branch and light from the second optical branch interfere at the central aperture forming a spectral oscillatory pattern having peaks; wherein the distance between the at least one groove and aperture is at least greater than fifty times a width of the at least one groove and operable to spectrally shift the spectral oscillatory pattern so that the most prominent peaks are positioned at the illumination wavelengths; and wherein the plasmonic interferometer sensor is operable such that a change in phase of the surface plasmon polaritons due to refractive index changes in the first optical arm relative to the light in the second optical arm causes a shift in the spectral oscillatory pattern to perform sensing measurements.