Patent ID: 8208776

Claim:
An optical control device including a plurality of line-defect waveguides provided in a photonic crystal, each line-defect waveguide including a multiplicity of dielectric pillars with a finite height arranged at lattice points of a two-dimensional Bravais lattice, said optical control device comprising: a first line-defect waveguide; a second line-defect waveguide provided with the dielectric pillars having a thickness different from that of the dielectric pillars of said first line-defect waveguide; and a third line-defect waveguide arranged between said first and second line-defect waveguides and provided with the dielectric pillars whose thicknesses are gradually varied from those of the dielectric pillars of said first line-defect waveguide to those of the dielectric pillars of said second line-defect waveguide along a wave guiding direction, wherein thicknesses of the dielectric pillars contained in the line defect of said first and second line-defect waveguides differ only with respect to those of the dielectric pillars contained in the line defect(s) of said first and second line-defect waveguides, and the thicknesses of dielectric pillars not contained in the line defect(s) of said first and second line-defect waveguides are equal.