| CPC G02B 6/14 (2013.01) [G02B 6/1228 (2013.01); G02B 6/125 (2013.01); G02F 2201/20 (2013.01); G02F 2201/205 (2013.01)] | 18 Claims |

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1. A method comprising:
coupling a first waveguide, comprising a first input waveguide, and a second waveguide, comprising a second input waveguide, in a first plurality of waveguides to a multimode waveguide delay device comprising a spiral delay line, the first waveguide and the second waveguide being coupled to a first end of the multimode waveguide delay device, the multimode waveguide delay device comprising a second end that is opposite of the first end,
the first waveguide being coupled to a first optical mode in the multimode waveguide delay device for coupling light from the first waveguide into the multimode waveguide delay device, and
the second waveguide being coupled to a second optical mode in the multimode waveguide delay device for coupling light from the second waveguide into the multimode waveguide delay device,
the second optical mode being different than the first optical mode,
coupling, at the second end of the multimode waveguide delay device, the first optical mode and the second optical mode from the multimode waveguide delay device to a second plurality of waveguides,
the first optical mode being coupled to a third waveguide, comprising a first output waveguide, of the second plurality of waveguides, and
the second optical mode being coupled to a fourth waveguide, comprising a second output waveguide, of the second plurality of waveguides, wherein the multimode waveguide delay device is configured to provide a uniform optical delay between the first end of the multimode waveguide delay device and the second end of the multimode waveguide delay device.
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