Patent ID: 9746607
Date: 2017-08-29
CPC Classifications: G02B

Claim:
1. A waveguide structure for optical coupling, the waveguide structure comprising: a first waveguide embedded in a cladding of lower refractive index than the first waveguide; a second waveguide of higher refractive index than the cladding and distanced from the first waveguide; and an intermediate waveguide, of which at least a part is arranged between overlapping portions of the first waveguide and the second waveguide, wherein the first waveguide and the second waveguide each comprise a tapered end for coupling light into and/or out of the intermediate waveguide, the tapered ends for the first waveguide and the second waveguide forming the overlapping portions of the first waveguide and the second waveguide, and wherein the intermediate waveguide is of higher refractive index than the cladding but of lower refractive index than the first and second waveguides.