Photonic crystal heterostructures resonant tunnelling, waveguides and filters

Photonic crystal heterostructures are concatenations of photonic crystals differing in refractive index or lattice geometry. They can be fabricated using self-assembly of colloidal spheres. In this paper we present a review of the devices enabled by such colloidal heterostructures, along with an envelope approximation used to efficiently study their properties. We show that the approximation is well suited for studying polymer photonic crystals. We also provide a comparison between the envelope approximation and a tight-binding method used to study defects in photonic crystals.