Self-assembly approach to metamaterials and plasmonics

Photonic crystals (PhCs), artificially created periodic structures of dielectric materials, hold promise for innovative light manipulation structures which can be viewed as a subclass of a larger family of metamaterials. A simple and inexpensive method to realize PhCs in opal configuration exploits the properties of self-assembly of colloidal nano-microspheres. These spheres and the derived self-assembled structures can be doped with different kinds of cromophores and can also coated by noble metals. In this sense, applications to active metamaterials and plasmonics-based devices, suitable as fluorescent markers,for luminescence enhancement are possible.In this presentation we give a survey of experimental activity realized in our Lab. In particular we present the recent results obtained on photonic crystals in silica inverse opal configuration activated with Er3+ions (Figure 1) [1,2]. The protocol followed to realize core-shell-like structures of Er3+-activated silica spheres, using a seed growth method (Figure 2), will be described [1,2].