Colorless Gridless Optical Network Node Architecture
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Solution Overview
Problem
Existing optical networks face challenges in flexibility and cost due to the complexity and expense of reconfiguring wavelength grids, as well as signal distortion and attenuation issues with conventional routing devices like ROADMs and WSSs.
Innovation Solution
A colorless, directionless, and gridless optical network architecture using passive optical multicast elements and configurable optical blocking elements that broadcast signals to all ports, allowing for flexible wavelength operation and network restoration without the need for wavelength filters or active elements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If ROADMs are used to provide reconfigurable optical routing, then routing flexibility is improved, but device complexity and cost increase due to active optical elements and channel filters
Solution Approach 1:
The patent extracts the wavelength filtering function from active ROADMs and implements it using passive optical elements. Specifically, it removes the need for active channel filters and replaces them with a passive optical circuit that uses wavelength-selective reflection and interference to achieve the same routing functionality without requiring power-consuming active components.
Solution Approach 2:
The patent replaces the mechanical/electronic control system of ROADMs with an all-optical passive system. Instead of using electronically controlled switches and active filters, the invention uses optical interference and resonance phenomena in passive waveguide structures to achieve wavelength-selective routing, thereby eliminating the need for active optical elements and electronic control mechanisms.
2Adaptability or versatility
If ROADMs with channel filters are used for wavelength routing, then routing capability is improved, but signal loss and distortion increase limiting the number of hops
Solution Approach 1:
The patent employs disposable-like passive optical elements that do not degrade with use. The passive waveguide structures and interferometric components maintain their optical properties over many hops without the wear and tear associated with active components, enabling signals to traverse multiple nodes with minimal cumulative loss.
Solution Approach 2:
The patent introduces a new dimensional approach to wavelength routing by using the optical field's spatial and spectral dimensions simultaneously. Instead of relying on sequential switching in the time domain, the invention exploits wavelength-dependent interference patterns and resonance conditions to achieve routing in the spectral dimension, reducing the need for repeated filtering operations that cause signal degradation.
3Device complexity
If fixed OADMs are used with assigned wavelengths, then network structure is simplified, but adaptability to wavelength changes is lost requiring replacement of devices
Solution Approach 1:
The patent introduces dynamic wavelength adaptability into what would otherwise be a static fixed OADM structure. The passive optical circuit incorporates tunable resonators and variable interference conditions that allow the same physical device to adapt its wavelength routing characteristics dynamically, combining the simplicity of fixed OADMs with the flexibility of reconfigurable systems.
Solution Approach 2:
The patent creates a universal optical routing device that can handle multiple wavelengths and routing configurations simultaneously. The passive waveguide structure with wavelength-selective elements is designed to be universally applicable across different wavelength channels, allowing a single device type to replace multiple wavelength-specific fixed OADMs while maintaining simplified network structure.
4Productivity
If wavelength grids are densified to transport more signals, then data bandwidth is improved, but signal interference and distortion increase
Solution Approach 1:
The patent applies local quality enhancement by creating highly selective wavelength routing at each individual node. The passive optical circuit uses localized resonant structures and interference patterns to precisely differentiate between closely spaced wavelengths, ensuring that each wavelength channel is routed accurately without interfering with adjacent channels, even in densely packed wavelength grids.
Solution Approach 2:
The patent introduces passive optical interference patterns as intermediaries between closely spaced wavelength channels. These interference patterns act as spectral filters that selectively pass desired wavelengths while blocking adjacent channels, preventing signal interference and distortion in densely multiplexed systems without requiring active filtering components.
Data Source
AI summary
An optical node includes an optical routing apparatus including N ports, N is an integer greater than 2, the optical routing apparatus configured to direct light that is input to each of the N ports to all of the other N ports, and a configurable optical blocking element located in line with at least one of the N ports. A method includes broadcasting a plurality of optical signals over a plurality of ports using a broadcast element, selectively receiving a desired signal from all of the plurality of optical signals at one of the plurality of ports, and blocking the plurality of signals via a blocking element in line with one of the plurality of ports thereby preventing a multiple path of the broadcast plurality of optical signals.