Demultiplexer
AssigneeRockley Photonics Limited
InventorsThomas Pierre Schrans, Andrea Trita, Adam Scofield
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Abstract
A demultiplexer for use in a wavelength division multiplexed system. The demultiplexer comprises: an input waveguide, configured to receive a wavelength division multiplexed signal; a demultiplexing element, configured to demultiplex the multiplexed signal received from the input waveguide into a plurality of multi-mode demultiplexed signal components; a multi-mode output waveguide, the multi-mode output waveguide being coupled to the demultiplexing element and configured to receive one of the multi-mode demultiplexed signal components; and a splitter, coupled to the multi-mode output waveguide, and configured to split the received multi-mode demultiplexed signal component into two single-mode outputs.
Claims11
A demultiplexer, for use in a wavelength division multiplexed system, the demultiplexer comprising:
- an input waveguide, configured to receive a wavelength division multiplexed signal;
- a wavelength demultiplexing element, configured to demultiplex the multiplexed signal received from the input waveguide into a plurality of multi-spatial-mode demultiplexed signal components respectively having a plurality of different wavelengths;
- a multi-spatial-mode output waveguide, the multi-spatial-mode output waveguide being coupled to the demultiplexing element and configured to receive one of the multi-spatial-mode demultiplexed signal components;
- and
- a splitter, coupled to the multi-spatial-mode output waveguide, and configured to split the received multi-spatial-mode demultiplexed signal component into two single-spatial-mode outputs and to provide each of the two single-spatial-mode outputs to a respective transfer waveguide, and
- wherein the demultiplexer includes an output Mach-Zehnder interferometer connected to each of the respective transfer waveguides and operable as a wavelength filter, each output Mach-Zehnder interferometer of the output Mach-Zehnder interferometers has two arms of different path lengths and is configured to multiplex two wavelengths that are equal distance from a channel center of the output Mach-Zehnder interferometer so that the frequency response of the output Mach-Zehnder interferometer is a flat-top response, and
- wherein the demultiplexer includes an input Mach-Zehnder interferometer connected between the input waveguide and the demultiplexing element, the input Mach-Zehnder interferometer having two arms of different path lengths, and the input Mach-Zehnder interferometer being operable as a wavelength filter.
A demultiplexer, for use in a wavelength division multiplexed system, the demultiplexer comprising:
- an input waveguide, configured to receive a wavelength division multiplexed signal;
- a wavelength demultiplexing element, configured to demultiplex the multiplexed signal received from the input waveguide into a plurality of multi-spatial-mode demultiplexed signal components respectively having a plurality of different wavelengths;
- a multi-spatial-mode output waveguide, the multi-spatial-mode output waveguide being coupled to the demultiplexing element and configured to receive one of the multi-spatial-mode demultiplexed signal components;
- and
- a splitter, coupled to the multi-spatial-mode output waveguide, and configured to split the received multi-spatial-mode demultiplexed signal component into two single-spatial-mode outputs and to provide each of the two single-spatial-mode outputs to a respective transfer waveguide,
- wherein the demultiplexer is a receiver and includes a waveguide photodiode, connected at a first end to one of the transfer waveguides and connected at a second end to the other of the transfer waveguides,
- wherein the two transfer waveguides are configured to provide the two single-spatial-mode outputs to the waveguide photodiode in counter propagating directions through the waveguide photodiode,
- wherein the two transfer waveguides are configured to have an equal group delay such that the two single-spatial-mode outputs arrive synchronously at the waveguide photodiode,
- wherein the waveguide photodiode is configured to absorb at least 90% of the signal received from either end within a half of a length of the waveguide photodiode, and
- wherein the transfer waveguides have a similar or substantially identical optical path length, and
- wherein the demultiplexer includes an input Mach-Zehnder interferometer connected between the input waveguide and the demultiplexing element, the input Mach-Zehnder interferometer having two arms of different path lengths, and the input Mach-Zehnder interferometer being operable as a wavelength filter.
Dependencies are inferred from the claim text.