Geometrical freedom for constructing variable size photonic bandgap structures

In order to study the design flexibility of photonic bandgap structures, we investigate different examples of 1D traditional Bragg layers and 2D photonic crystals. We have also considered a simple case of 3D woodpile structures. It turns out that in systems with large gaps, the evanescent waves penetrate into the bulk only distances comparable to one lattice constant. Therefore confinement of light can also be achieved without long range order, which leads to the introduction of novel photonic bandgap designs. Adhering to some constraints, the changes in the photonic bandgap in disordered structures are negligible. The important quantity to characterize the presence or absence of modes is the local photonic density of states, however bandgap phenomena in size and position disordered arrangements can also be verified with plane wave supercell calculations as well as finite difference time domain techniques.