Scalable optical demultiplexing arrangement for wide band dense wavelength division multiplexed systems
First Claim
1. An apparatus for demultiplexing a wavelength division multiplexed optical signal having a plurality of optical channels, the apparatus comprising:
- an optical muter for distributing a copy of the wavelength division multiplexed optical signal to each of a plurality of output ports;
two or more optical demultiplexers, each directly coupled to one of the plurality of output ports, each of the two or more demultiplexers being operable to receive the entire wavelength division multiplexed optical signal and further operable to demultiplex a respective group of optical channels such that an optical channel is demultiplexed by only one optical demultiplexer, wherein each of the two or more optical demultiplexers is an arrayed waveguide grating; and
a plurality of optical filters coupled to selected output ports of the two or more optical demultiplexers, each of the plurality of optical filters being transmissive with respect to at least one selected wavelength within the respective group of demultiplexed optical channels and reflective with respect to other wavelengths, wherein the optical router includes one or more unused output ports, each of which is capable of being directly coupled to an additional optical demultiplexer adapted for receiving the entire wavelength division multiplexed optical signal and for demultiplexing other optical channels such that additional optical demultiplexers can be added to the arrangement without disrupting operation of the two or more optical demultiplexers, wherein each of the additional optical demultiplexers is an arrayed waveguide grating.
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Accused Products
Abstract
Substantial reduction in crosstalk and improved scalability for supporting high channel counts in dense wavelength division multiplexed (DWDM) systems is achieved in an optical demultiplexer arrangement that partitions the total number of input optical channels into separate demultiplexer modules, demultiplexes smaller groups of optical channels in the separate demultiplexer modules, and filters the individual optical channels at the outputs of the separate demultiplexer modules. Partitioning the total number of channels into smaller demultiplexing groups and post-filtering a reduced number of demultipexed optical channels reduces the number of non-adjacent channels that can contribute to the total crosstalk level. The modularity of the optical demultiplexer arrangement results in smaller device footprints and smaller free spectral ranges associated with the demultiplexer modules. This modularity also allows for future system upgrades without redesign and without disruption to existing service. In one illustrative embodiment, the optical demultiplexer arrangement includes a splitter or filter for directing the multi-wavelength input optical signal to one or more demultiplexer modules. Each of the demultiplexer modules separates a received multi-wavelength optical signal into individual wavelength channels. The individual wavelength channels are then supplied to bandpass post-filters which are coupled to each of the outputs of the demultiplexer modules.
24 Citations
11 Claims
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1. An apparatus for demultiplexing a wavelength division multiplexed optical signal having a plurality of optical channels, the apparatus comprising:
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an optical muter for distributing a copy of the wavelength division multiplexed optical signal to each of a plurality of output ports;
two or more optical demultiplexers, each directly coupled to one of the plurality of output ports, each of the two or more demultiplexers being operable to receive the entire wavelength division multiplexed optical signal and further operable to demultiplex a respective group of optical channels such that an optical channel is demultiplexed by only one optical demultiplexer, wherein each of the two or more optical demultiplexers is an arrayed waveguide grating; and
a plurality of optical filters coupled to selected output ports of the two or more optical demultiplexers, each of the plurality of optical filters being transmissive with respect to at least one selected wavelength within the respective group of demultiplexed optical channels and reflective with respect to other wavelengths, wherein the optical router includes one or more unused output ports, each of which is capable of being directly coupled to an additional optical demultiplexer adapted for receiving the entire wavelength division multiplexed optical signal and for demultiplexing other optical channels such that additional optical demultiplexers can be added to the arrangement without disrupting operation of the two or more optical demultiplexers, wherein each of the additional optical demultiplexers is an arrayed waveguide grating. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A method of upgrading the demultiplexing capability of a wavelength division multiplexed (WDM) system capable of transporting a WDM optical signal having a plurality of optical channels of different wavelengths, the method comprising:
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distributing a copy of a WDM optical signal to each of a plurality of transmission paths via output ports of an optical splitter;
at two or more of the output ports of the optical splitter, receiving the entire WOM optical signal at a respective arrayed waveguide grating (AWG)-based optical demultiplexer and independently demultiplexing selected ones of the plurality of optical channels from the entire WDM optical signal so that an optical channel is demultiplexed in only one of the plurality of transmission paths corresponding to one of the output ports of the optical splitter, wherein each of the respective AWG-based optical demultiplexers is directly coupled to the optical splitter, and filtering each of the demultiplexed optical channels;
endat one or more previously unused output ports of the optical splitter, directly coupling an additional AWG-based optical demultiplexer adapted for receiving the entire WDM optical signal and for demultiplexing other optical channels.
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Specification