Colloidal photonic superlattices

Abstract
We report on the fabrication and optical characterization of photonic superlattices comprised of sequentially grown stacks of colloidal photonic crystals. The superlattice periodicity induces the formation of minibands due to folding of the photonic band structure. This represents the first instance in which midgap states have been incorporated into a colloidal photonic crystal via a specifically engineered structural modification.