Patent ID: 7483130

Claim:
A planar optical platform for generating a Raman signal from a foreign object; comprising: an input region for receiving optical radiation; a plasmonic band structure region optically coupled to the input region, the plasmonic band structure region comprising a layer of a first material patterned with an array of sub-regions of a second material, the first material having a first refractive index and the second material having a second refractive index, a side-wall of each sub-region being coated with a metallic or metallodielectric layer, wherein the array of sub-regions give rise to a plasmonic band structure, and wherein, in use, each sub-region confines at least one plasmon resonance excited by optical radiation coupled into the plasmonic band structure region which gives rise to a Raman signal from a foreign object placed proximate the plasmonic band structure region; and an output region for extracting optical radiation, the output region optically coupled to the plasmonic band structure region.