Fundamental tests of a dielectric photonic bandgap waveguide in the microwave region

Summary form only given. We constructed hollow-core photonic bandgap waveguides surrounding a central hollow core with a two-dimensional photonic bandgap structure. This structure is fabricated by stacking together a array of hollow cylinders in a hexagonal closed packed lattice structure, but omitting the central cylinder and its six nearest neighbors. The central hole of the fiber thus consists of seven missing central cylinders of this 2D lattice, and this hole can be considered to be a defect in the otherwise perfectly periodic structure. Light can be guided down this hole in a symmetric fundamental mode. Our goal is completely characterize the nature of this mode and the band gap structure.