Patent ID: 7606493

Claim:
An optical multiplexer-demultiplexer comprising: (a) an optical waveguide; and (b) an alignable diffraction grating, wherein the alignable diffraction grating is movable independently of the optical waveguide, and wherein said optical waveguide comprises i. at least one core for alignment of the alignable diffraction grating; ii. a core for incident light; and iii. a plurality of cores for outgoing light, wherein a width of the cores for outgoing light is more than 1.5 times a width of the core for incident light; and wherein the alignable diffraction grating comprises i. a surface provided with unevenness having a predetermined period; and ii. a metal coated on the surface, wherein the alignable diffraction grating is disposed so the metal coated on the surface contacts said optical waveguide in order to reflect light rays.