PLANAR WAVEGUIDE STRUCTURE HAVING SEGMENTED TRENCH AND CLOSELY SPACED AND OPTICALLY ISOLATED WAVEGUIDE

摘要

PROBLEM TO BE SOLVED: To control optical coupling and crosstalk in a closely spaced and weakly confined waveguide arrangement. SOLUTION: The structure has: a first optical waveguide formed on a substrate, the waveguide weakly confining a first optical signal propagating therein; a second waveguide formed on the substrate and weakly confining a second optical signal propagating therein; and a trench formed in the substrate between the first waveguide and the second waveguide. The first waveguide has the optical propagation axis and a characteristic length measured along the optical propagation axis. The second waveguide is in close proximity to the first optical waveguide. The trench has a characteristic length measured parallel to the optical propagation axis of the first waveguide. The characteristic length of the trench is substantially shorter than the characteristic length of the first waveguide. The trench has a substance having a low refractive index. COPYRIGHT: (C)2005,JPO&NCIPI