We describe the fabrication and characterisation of arrays of metallic plasmon resonant nanorings, each of which are formed from two semicircles of different radius. We show that using a dual semicircle structure defined by electron beam lithography can result in closely spaced localized plasmon resonant peaks in the visible region, which cannot be achieved using a simpler nanoring structure with one radius. The advantage of producing two closely spaced resonant peaks is a structure that can be used for Raman sensing purposes at two different wavelengths.
- localized surface plasmon
- electron beam lithography
- metallic plasmon resonant nanorings