Patent ID: 11971573
Assignee: TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY LTD.
Field: Optics (Instruments)
Classification: CPC G | IPC G

Claim 15:
16. A method of fabricating an optical coupler having a first light receiving end and a second light output end opposite the first light receiving end, said method comprising:
forming a cladding from a cladding material having a first index of refraction; and
forming a plurality of waveguide core layers contained within the cladding from a core material having a second index of refraction greater than the first index of refraction, said waveguide core layers being (i) stacked one over another, (ii) spaced apart one from another and (iii) extending from the first light receiving end of the optical coupler longitudinally through the cladding toward the second light output end of the optical coupler;
wherein said plurality of waveguide core layers are arranged such that light energy associated with light that enters outer ones of the plurality of waveguide core layers at the first light receiving end of the optical coupler is conveyed toward an interior one of the plurality of waveguide core layers via evanescent coupling between adjacent ones of the plurality of waveguide core layers; and
wherein the plurality of waveguide core layers comprises:
a central waveguide core layer that extends from the light receiving end to the light output end of the optical coupler;
a pair of outermost waveguide core layers arranged on opposite sides of the central waveguide core layer; and

a pair of intermediate waveguide core layers arranged on opposite sides of the central waveguide core layer and interposed between the outermost waveguide core layers and the central waveguide core layer.