Patent ID: 7136564

Claim:
A method for fabricating an optical apparatus, comprising: forming a first planar optical waveguide comprising a first waveguide core within a first cladding, an upper surface of the first cladding over the first core being substantially flat along at least a portion of the length thereof and thereby forming a first substantially flat waveguide upper cladding surface; forming at least one additional area of first core material within the first cladding, the additional area of first core material forming a corresponding substantially flat first structural upper cladding surface substantially parallel to the first substantially flat waveguide upper cladding surface; forming a second planar optical waveguide comprising a second waveguide core within a second cladding, an upper surface of the second cladding over the second core being substantially flat along at least a portion of the length thereof and thereby forming a second substantially flat waveguide upper cladding surface; forming at least one additional area of second core material within the second cladding, the additional area of second core material forming a corresponding substantially flat second structural upper cladding surface substantially parallel to the second substantially flat waveguide upper cladding surface; and assembling the first and second planar optical waveguides together with at least portions of their corresponding substantially flat structural upper cladding surfaces positioned against one another and with at least portions of their corresponding waveguide upper cladding surfaces facing one another, thereby positioning the first and second planar optical waveguides for optical transverse-coupling between the first and second cores along corresponding transverse-coupled portions thereof, wherein: the additional area of first core material is positioned so as to substantially avoid optical coupling with the first waveguide core and, upon assembly of the first and second planar optical waveguides, to substantially avoid optical coupling with the second waveguide core; and the additional area of second core material is positioned so as to substantially avoid optical coupling with the second waveguide core and, upon assembly of the first and second planar optical waveguides, to substantially avoid optical coupling with the first waveguide core.