High transmission through sharp bends using photonic crystal polycrystalline structures

Summary form only given. A hybrid photonic crystal structure is presented as a candidate to enhance transmission through sharp photonic crystal waveguide bends built on a perforated dielectric slab. This structure, which we refer to as a polycrystalline structure, combines two photonic crystal lattices of different crystalline parameters; such as different lattice constants over a localized region. Polycrystalline photonic crystal structures offer the ability to minimize both reflections as well as radiation losses that a propagating wave might encounter while undergoing through a sharp corner. The availability of polycrystalline structures in photonic crystals opens a broad range of possibilities for optical device development. Numerical experiments are performed using two-dimensional finite difference time-domain (FDTD) methods.