Patent ID: 9746614
Date: 2017-08-29
CPC Classifications: G02B,H04J

Claim:
1. A photonic device, comprising: a substrate; an input/output multimode optical waveguide formed on the substrate and configured to support light in different optical waveguide modes as an input/output optical port of the substrate, wherein the input/output multimode optical waveguide includes a tapered waveguide terminal that decreases in cross section towards a tip of the tapered waveguide terminal; an optical multimode multiplexing/demultiplxing coupler coupled to the input/output multimode optical waveguide to either receive different optical signals in different optical single modes to combine the received different optical signals into a multimode signal to the input/output multimode optical wave, or to receive a multimode optical signal from the input/output multimode optical wave to split the received multimode optical signal into different optical signals in different optical single modes; a plurality of single mode optical waveguides formed on the substrate and optically coupled to the input/output multimode optical waveguide to guide, respectively, the different optical signals in different optical modes, either from the input/output multimode optical waveguide or to the input/output multimode optical waveguide; optical processing modules formed on the substrate and coupled to the single mode optical waveguides, respectively, wherein each optical processing module is configured to process a respective optical signal of a single optical mode; and a multimode optical fiber structured to support light in different optical fiber modes, the multimode optical fiber located above the input/output multimode optical waveguide and optically coupled to the input/output multimode optical waveguide via evanescent coupling to allow light to be coupled between the optical fiber and the input/output multimode optical waveguide, wherein the multimode optical fiber includes a tapered fiber terminal which decreases in cross section towards a tip of the tapered fiber terminal and thus tapers in an opposite direction from tapering of the tapered waveguide terminal, wherein the tapered fiber terminal and the tapered waveguide terminal spatially overlap with each other to cause adiabatic transition of guided light and to cause coupling of different modes between the tapered fiber terminal and the tapered waveguide terminal.