Brillouin Optical Sensing Beat Frequency Cost Reduction
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Solution Overview
Problem
The widespread adoption of Brillouin optical time domain reflectometry (BOTDR) is limited due to its complex configuration and high introduction costs, primarily because the light receiving unit requires a wide frequency bandwidth to measure Brillouin frequency shift, making the components expensive.
Innovation Solution
A Brillouin optical sensing device and method using two optical fibers with different Brillouin frequency shift characteristics arranged in parallel, measuring and analyzing a beat signal from multiplexed Brillouin scattering lights to reduce the necessary frequency bandwidth, allowing for the use of less expensive reception units and commercially available optical fibers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a light receiving unit with wide frequency bandwidth (≥10 GHz) is used to measure Brillouin frequency shift, then measurement precision is improved, but device cost increases
Solution Approach 1:
The patent merges the Brillouin scattering light from two different optical fibers by coupling them together, creating a beat signal that contains the frequency shift information. This combining approach allows the use of narrower bandwidth receivers since the frequency difference is encoded in the beat frequency rather than requiring direct measurement of the high-frequency Brillouin shift
Solution Approach 2:
The patent introduces an intermediary beat signal as a mediator between the Brillouin scattering light and the measurement process. By measuring the beat frequency between two Brillouin signals from fibers with different characteristics, the system indirectly obtains the frequency shift information without requiring direct high-bandwidth measurement of the Brillouin signal itself
2Measurement precision
If a light receiving unit with wide frequency bandwidth (≥10 GHz) is used to measure Brillouin frequency shift, then measurement precision is improved, but component cost increases
Solution Approach 1:
The patent merges the Brillouin scattering light from two different optical fibers by coupling them together, creating a beat signal that contains the frequency shift information. This combining approach allows the use of narrower bandwidth receivers since the frequency difference is encoded in the beat frequency rather than requiring direct measurement of the high-frequency Brillouin shift
Solution Approach 2:
The patent enables the use of cheaper, commercially available optical fibers with standard characteristics instead of requiring specialized high-performance fibers. By using two conventional fibers with slightly different properties and measuring their beat signal, the system achieves the measurement goal with lower-cost components
3Adaptability or versatility
If BOTDR configuration is used for Brillouin optical sensing, then distributed strain and temperature monitoring capability is achieved, but device complexity increases
Solution Approach 1:
The patent merges the Brillouin scattering light from two different optical fibers by coupling them together, creating a beat signal that contains the frequency shift information. This combining approach allows the use of narrower bandwidth receivers since the frequency difference is encoded in the beat frequency rather than requiring direct measurement of the high-frequency Brillouin shift
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 reduces the introduction costs of Brillouin optical sensing by narrowing the frequency bandwidth required for reception units, improving measurement accuracy and making the technology more cost-effective while maintaining the ability to monitor strain and temperature changes in optical fibers.
Implementation Method 1
an optical pulse is launched into an optical fiber to be measured, and a time response of Brillouin scattering light generated in the measured optical fiber is analyzed
Implementation Method 2
measuring and analyzing a beat signal obtained by multiplexing Brillouin scattering lights of the optical fibers
Data Source
AI summary
An object of the present invention is to provide a Brillouin optical sensing device and an optical sensing method capable of reducing introduction costs. The Brillouin optical sensing device according to the present invention includes: a sensing fiber 90 in which a plurality of optical fibers having Brillouin frequency shift characteristics different from each other are arranged in parallel; an optical measuring instrument 11 that launches an optical pulse into at least two of the optical fibers of the sensing fiber 90 to generate Brillouin scattering lights and measures a beat frequency of a beat signal between the Brillouin scattering lights at any position of the sensing fiber 90; and an arithmetic processing unit 12 that acquires a physical quantity of the sensing fiber 90 at said any position based on the beat frequency acquired by the optical measuring instrument 11.