Self-assembly approach to optical metamaterials

Abstract

Photonic crystals can be viewed just as a subclass of a larger family of material systems called metamaterials in which the properties largely derive from the structure rather than from the material itself. Opals have only a relatively recent history as photonic bandgap materials and have received a strong thrust from their adequacy as scaffoldings for further templating other materials with photonic applications for instance. The tortuous route from materials to devices might perhaps find reward in the ease and low cost of fabrication of these materials. In this paper we present a review of recent work and work under way in our laboratory tending towards synthesis based on self-assembly to realize metamaterials in the optical range. This comprises the formation of the templates (opals) and subsequent synthesis of guest materials such as semiconductors, metals and insulators. The possibility of further processing allows additional two-dimensional and quasi-two-dimensional patterning for the design of new structures. In this paper we show how the raw matter can be checked for quality and learn how to use its optical properties to evaluate application potential. Issues relating to the optical properties (such as crystalline quality, finite size effects and infiltration with other materials) are examined. We show some examples where opals are used to pattern the growth of other materials with photonic applications (such as metals and semiconductors) and developments leading to both vertical and lateral engineering are shown.

Anisotropy of weak light scattering in thin opal films

“…Samples were mounted taking into account the lattice orientation that was identified by using the surface light diffraction pattern of the opal film. 15 Opal films were oriented so that the increase in incidence angle corresponds to scanning the wavevector along the LKLЈ line on the surface of the opal Brillouin zone.…”

Design of photonic structures by sol–gel-derived silica nanospheres

“…3D-PCs and their properties largely derive from the structure, rather than from the material itself. Opals have only a relatively recent history as photonic bandgap materials and have received a strong thrust from their adequacy as scaffoldings [2]. These structures lead to photonic devices such as switches, mirrors, filters and superprisms [3].…”

Optical Nonlinearities of Colloidal Metal Quantum Dot - Glass Composites for Nanophotonics

“…Different approaches have been made to synthesize the negative refractive index materials. These include fabricating a multilayer metal-dielectric stack by using focused ion-beam milling [79], printed circuit board technology [80], self assembly approach [81,82], fabricating regular arrays of metal pillars by high-resolution electron-beam lithography on a glass substrate [83,84], and by sol-gel technique [85]. Regular arrays of gold and silver pillars fabricated by high resolution electron-beam lithography or by ion-implantation, both on glass substrates have been reported to have negative refractive index.…”