Patent ID: 10578803

Abstract:
An optical demultiplexer/multiplexer, comprising: a multimode interference waveguide; at least one first coupling waveguide which meets the multimode interference waveguide at least one first location and a plurality of second coupling waveguides which meet the multimode interference waveguide at a plurality of second locations which are spaced in a direction of transmission in relation to the at least one first location, with the at least one first coupling waveguide and the second coupling waveguides together with the multimode interference waveguide providing a first angled multimode interferometer which operates to demultiplex a first optical signal having optical channels of a plurality of wavelengths or multiplex optical signals of a plurality of wavelengths into a first optical signal having optical channels of the plurality of wavelengths; at least one third coupling waveguide which meets the multimode interference waveguide at least one third location and a plurality of fourth coupling waveguides which meet the multimode interference waveguide at a plurality of fourth locations which are spaced in a direction of transmission in relation to the at least one third location, with the at least one third coupling waveguide and the plurality of fourth coupling waveguides together with the multimode interference waveguide providing a second angled multimode interferometer which operates to demultiplex a second optical signal having optical channels of a plurality of wavelengths or multiplex optical signals of a plurality of wavelengths into a second optical signal having optical channels of the plurality of wavelengths; whereby the demultiplexer/multiplexer provides for the demultiplexing/multiplexing of first and second optical signals having optical channels of a plurality of wavelengths. In a further embodiment the first coupling waveguide of an optical demultiplexer/multiplexer comprising a first angled multimode interferometer is stepped or tapered in order to couple a signal having a broadened spatial, or spectral, profile. In another embodiment of an optical demultiplexer/multiplexer comprising a first angled multimode interferometer a plurality of first coupling waveguides are coupled to a photonic structure which provides a plurality of output signals having substantially equal intensity and a phase difference, also in order to couple a signal or signals having a broadened spatial, or spectral, profile. In yet another embodiment of an optical demultiplexer/multiplexer comprising a first angled multimode interferometer the multimode interference waveguide includes a reflector at one end.