Patent ID: 7046878

Claim:
A channel add/drop filter comprising: a first 2D photonic crystal including a first waveguide made from a line defect and a first cavity made from a point defect, said first cavity acting to take in light of a specific wavelength from said first waveguide and radiate it outside said first photonic crystal and conversely acting to introduce light of a specific wavelength into said first waveguide from outside of said first photonic crystal; a second 2D photonic crystal including a second waveguide having substantially the same characteristics as said first waveguide, and a second cavity having substantially the same characteristics as said first cavity; and means for optically connecting said first and second waveguides in series so as to have light in common, and so that when the principal plane of said first 2D photonic crystal and the electric-field vector of the light within said first waveguide form an arbitrary angle α, the principal plane of said second 2D photonic crystal and the electric-field vector of the light within said second waveguide form an angle of α+(π/2).