Bidirectional WDM Fiber Sharing for Communication and Sensing

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Solution Overview

Problem

Current optical communication systems face challenges in integrating simultaneous optical communications and sensing on a common optical fiber due to high instantaneous operating power of fiber sensing systems, which degrades communication performance and requires separate fibers to avoid interference.

Innovation Solution

A bidirectional optical fiber communication and sensing WDM architecture that shares the same fiber transmission band, using standard WDM multiplexers and de-multiplexers to coexist communications channels and sensing channels, reducing nonlinear interactions and employing techniques to suppress ASE noise, allowing for simultaneous operation without additional computational resources.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If separate optical fibers are used for communications and sensing, then interference between systems is eliminated, but device complexity and resource consumption increase

Engineering Contradiction:

Improvesystem performanceVSAvoidfiber configuration

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines communication and sensing systems onto a single optical fiber by using bidirectional WDM architecture. The sensing system transmits pulses in one direction while communication signals travel in the opposite direction, allowing both systems to coexist on the same fiber without interference. This merging eliminates the need for separate fibers while maintaining system reliability.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The optical fiber is designed to serve multiple functions simultaneously - both communication and sensing operations. The WDM multiplexer/demultiplexer enables the single fiber to handle different wavelength channels for different purposes, making the fiber infrastructure universal and multi-functional rather than dedicated to a single purpose.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Measurement precision

If optical pulse reflectometry is used for fiber sensing, then sensing capability is achieved, but communication performance degrades due to high instantaneous power

Engineering Contradiction:

Improvesensing capabilityVSAvoidcommunication performance

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The patent segments the optical spectrum into different wavelength channels using WDM technology. The sensing system operates at specific wavelengths while communication systems operate at other wavelengths, separating their spectral domains. This segmentation allows both systems to function simultaneously without the high instantaneous power of sensing pulses degrading communication performance.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The WDM multiplexer and demultiplexer act as intermediary devices that separate and direct different wavelength channels. They mediate between the sensing and communication systems, ensuring that high-power sensing pulses do not interfere with communication signals by routing them through different spectral paths.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Reliability

If bidirectional WDM fiber sharing is implemented, then nonlinear interaction is reduced, but ASE noise from EDFAs affects sensing signals

Engineering Contradiction:

Improvesignal interferenceVSAvoidASE noise

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent converts the harmful ASE noise from EDFAs into a manageable parameter by using narrowband optical filters. The filters are designed to pass only the specific sensing wavelengths while blocking the broader ASE noise spectrum. This approach transforms the noise problem into a filtering opportunity, allowing the system to benefit from EDFA amplification while suppressing their unwanted noise output.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

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 approach eliminates the need for multiple fibers, simplifies the arrangement, and improves performance by reducing signal interference and noise, enabling efficient simultaneous communication and sensing on a single fiber with better fiber loss characteristics.

Implementation Method 1

bidirectional WDM fiber sharing such that communications channels and optical fiber sensing channel(s) may coexist on the same fiber

Methodology Applied

Scientific EffectWavelength Division Multiplexing:

Implementation Method 2

in-line erbium-doped fiber amplifiers (EDFAs) used for communications

Methodology Applied

Scientific EffectErbium-doped fiber amplification:

Implementation Method 3

distributed fiber sensing (DFS) systems, methods, and structures—including distributed vibration sensing (DVS), distributed acoustic sensing (DTS), and Brillouin optical time domain reflectometry (BOTDR), changes in optical fiber may be detected and located by using optical pulse interrogation methods

Methodology Applied

Scientific EffectOptical pulse reflectometry:

Data Source

PatentUS11463171B2Bidirectional optical communication and sensing WDM architecture using same fiber transmission band

Publication Date: 2022.10.04 NEC CORP

AI summary

Aspects of the present disclosure describe systems, methods and structures providing bidirectional optical fiber communication and sensing using the same fiber transmission band and bidirectional WDM fiber sharing such that communications channels and optical fiber sensing channel(s) coexist on the same fiber. As a result, nonlinear interaction between communications channels and interrogating pulse(s) of sensing are much reduced or eliminated.