Patent ID: 7619724

Claim:
A device for detecting changes in the refractive index of a dielectric medium ( 200 ), this device comprising: at least one metallic layer ( 300 ) configured to be placed in contact with the dielectric medium ( 200 ); at least one light source ( 20 ) configured to direct transversal magnetic polarized light towards said metallic layer, so that the light falls on said metallic layer; coupling means ( 10 ) associated to said light source ( 20 ) and to said metallic layer ( 300 ), so that the light can excite surface plasmon resonance on the metallic layer when falling on the metallic layer; at least one detector ( 31 ) configured to receive light reflected by the metallic layer and to detect at least one feature of said light; wherein the metallic layer contains ferromagnetic material; characterized in that the device further comprises magnetization means ( 50 ) configured to magnetize the metallic layer ( 300 ).