Advanced photonic crystal architectures from colloidal self-assembly techniques

We describe two different types of novel architectures based on photonic crystals of sub-micron colloids. The first involves the formation of photonic superlattices from colloidal photonic crystals. The superlattice periodicity induces the formation of minibands due to folding of the photonic band structure. This represents a way by which mid-gap states can be incorporated into a colloidal photonic crystal via a specifically engineered structural modification. The second idea involves applying the superprism concept to three-dimensionally periodic structures. Near a photonic band edge, the diffraction angle is strongly dependent on wavelength. We analyze this effect in the context of macroporous polymer thin films formed from colloidal crystal templates.