Wavelength Identification Sensor for WDM Networks

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Solution Overview

Problem

Wavelength division multiplexing (WDM) networks face challenges in identifying and analyzing wavelengths due to potential mismatches, which can lead to optical path blockages and difficulties in setting up and troubleshooting, especially in complex configurations like DWDM inside CWDM or WDM on PON, where wavelength selective devices need correct connection but may suffer from labeling errors or physical identification issues.

Innovation Solution

A wavelength identification and analysis sensor system using multi-wavelength or tunable optical reflectometry that transmits different wavelengths and analyzes returned signals to detect the wavelength associated with an input or output of wavelength selective devices, enabling single-end identification and differentiation of wavelength mismatches, insertion loss measurement, and spectral profile analysis without requiring disconnection of multiplexers or de-multiplexers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional wavelength identification methods are used in WDM networks, then setup and troubleshooting can be performed, but wavelength mismatches can occur leading to optical path blockages and identification difficulties

Engineering Contradiction:
Improvewavelength identification accuracyVSAvoidsystem complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

An optical circulator is introduced as an intermediary component between the optical fiber and the wavelength selective device. The circulator directs light from the fiber to the wavelength selective device and routes the reflected signal to the optical detector, enabling wavelength identification without disrupting the existing WDM network architecture or requiring additional complex equipment.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The wavelength selective device itself is utilized to perform wavelength identification by exploiting its inherent wavelength-selective reflection property. When a test signal passes through the device, wavelengths matching the device's selection are reflected back, allowing the system to automatically identify its own operational wavelength without external intervention or complex measurement equipment.

Inventive Principle:
Principle #25Self-service

2Productivity

If wavelength selective devices are connected in complex configurations like DWDM inside CWDM or WDM on PON, then network capacity increases, but wavelength identification and troubleshooting become more difficult

Engineering Contradiction:
Improvenetwork capacityVSAvoidwavelength identification difficulty
Core Design Contradiction:
ProductivityVSDifficulty of detecting and measuring

Solution Approach 1:

The system employs feedback by detecting the reflected signal from the wavelength selective device and analyzing its characteristics. The optical detector measures the intensity of the reflected light, which provides feedback information about wavelength matching. This feedback mechanism enables automatic wavelength identification and troubleshooting even in complex nested WDM configurations, as each device's reflection characteristic can be independently measured and analyzed.

Inventive Principle:
Principle #23Feedback

3Reliability

If optical path blockages occur due to wavelength mismatches, then network performance degrades, but identification and resolution of the issue become time-consuming

Engineering Contradiction:
Improveoptical path connectivityVSAvoidtroubleshooting time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The system performs preliminary wavelength verification by continuously or periodically measuring the reflected signal from the wavelength selective device. This preliminary action detects wavelength mismatches before they cause optical path blockages or performance degradation. By proactively identifying potential issues, the system prevents network outages and reduces troubleshooting time, as problems are detected and can be addressed before they impact service.

Inventive Principle:
Principle #10Preliminary action

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This solution allows for efficient identification and analysis of wavelengths in WDM systems, reducing the risk of optical path blockages and simplifying setup and troubleshooting by providing accurate wavelength matching and spectral profiling, even in complex configurations, thereby enhancing network reliability and maintenance efficiency.

Implementation Method 1

transmitting, by a wavelength transmitter (604), test signals on a plurality of wavelengths into an input or output of a wavelength selective device (608)

Methodology Applied
Scientific EffectOptical transmission: Light

Implementation Method 2

detecting (620) returned signals from the input or output of the wavelength selective device (608)

Methodology Applied
Scientific EffectOptical reflection: Reflection

Data Source

PatentEP3346620B1Wavelength identification and analysis sensor
Publication Date: 2024.05.29 VIAVI SOLUTIONS INC(US)
  • EP3346620B1 patent drawingFigure 1
  • EP3346620B1 patent drawingFigure 2
  • EP3346620B1 patent drawingFigure 3

AI summary

According to examples, a wavelength identification and analysis sensor may include a wavelength transmitter, operably connectable to an input or output of a wavelength selective device of a wavelength division multiplex (WDM) network, to transmit test signals on a plurality of wavelengths into the input or output of the wavelength selective device of the WDM network. A wavelength analyzer is to detect returned signals from the input or output of the wavelength selective device of the WDM network, with each returned signal being associated with one of the transmitted test signals. Further, the wavelength analyzer is to analyze the returned signals and identify, based on the analysis of the returned signals, a wavelength associated with the input or output of the wavelength selective device of the WDM network.