Nonlinear optical pulse propagation experiments in photonic bandgap materials

Periodic dielectric structures, often called photonic bandgap materials, have now expanded from simple gratings to engineered structures in one, two and three dimensions that can be tailored with a wide variety of amplitude, phase, and defect structures. Photonic bandgap systems include one-dimensional fiber gratings, two dimensional planar waveguides with dielectric arrays, and three dimensional arrays. Photonic bandgap materials include glasses, organic materials and semiconductors. Optical dispersion is very strong and varies rapidly near the photonic bandgap where forward and backward traveling waves are strongly coupled by the periodic structure. The effective linear velocity of an optical pulse goes to zero at the edge of the gap. These linear characteristics can be engineered over distances of from a few wavelengths to meters depending an the magnitude of the index variation in the periodic dielectric. The authors discuss their recent experiments studying soliton propagation and soliton dynamics in novel fiber grating structures and highly nonlinear materials