Bound states in photonic crystal waveguides and waveguide bends

Abstract

We investigate the mechanism for the appearance of bound states in two-dimensional photonic crystal waveguides and contrast it with the corresponding mechanism for conventional guides. It is shown that the periodicity of the photonic crystal can give rise to frequency ranges above cutoff where no guided modes exist in the waveguides. Such mode gaps make possible the creation of bound states in constrictions and in bends. Bound states are found to correspond to analogous cavity modes and it is shown that their appearance strongly depends on the lattice geometry and cannot be described in a one-dimensional framework.

Designing finite-height two-dimensional photonic crystal waveguides

“…Creating point-defects and line-defects in these crystals may lead to novel microcavities and waveguides. [3][4][5][6][7][8][9][10][11][12] Numerical calculations have shown that transmission coefficients above 98% for a 90°bend are possible for a crystal waveguide based on a large air line defect. 7 Design parameters for photonic crystals that result in large photonic band gaps may be found in the literature ͑see for example Refs.…”

Kink propagation and trapping in a two-dimensional curved Josephson junction

“…6 Spectral and transport characteristics of quantum electron channels 7 and waveguides in photonic crystal 8 are essentially modified by the existence of segments with finite curvature.…”

Photonic crystals in the optical regime — past, present and future

“…there is nowhere else for it to go to. Sharp bends and large-angle Y-junctions have been computationally`demonstrateda with virtually no excess losses [120,121]. These are impressive results that certainly point in the right direction.…”