Introduction.
Progress in optics is intimately connected to the development of novel optical materials. This includes advances in synthesizing such materials as well as improvements in their theoretical understanding. Photonic Crystals represent a particularly lucid illustration of this principle: The advent of advanced microstructuring techniques has allowed the realization of two- and three-dimensional periodic arrays on sub-micron scales that provide Bragg-scattering for electromagnetic waves with frequencies in the near IR and the visible. Photonic band structure computations accurately predict crystal structures that posses complete photonic bandgaps and the minimal refractive index contrast that is needed to open them. The controlled fabrication, characterization and optimal design of cavities and waveguiding structures in photonic band gap materials represents another fascinating challenge for material scientists, spectroscopists and theorists alike. Finally, the incorporation of nonlinear and optically active materials into Photonic Crystal structures along with a detailed understanding of the optical properties of the resulting composite systems, may enhance the technological utility of Photonic Crystals over and above the conventional linear structures.
C M
CM
de Sterke
K
K
Busch