Modeling photonic crystal interfaces and stacks: impedance-based approaches

In many research areas, the reflective properties of a bulk medium are characterized by its impedance or an impedance-like quantity. Such a quantity is essential for the efficient design of stacked structures such as antireflection coatings and thin-film filters. For 2D photonic crystals and metamaterials, the literature contains multiple definitions of impedance, not all of which are consistent. We review these proposed definitions, evaluate their regions of applicability, and numerically test their accuracy in a variety of salient photonic crystal examples. (C) 2013 Optical Society of America