Fiber Optic Sensor Frequency Multiplexing for High-Frequency Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current optical fiber sensors for boreholes are limited by exclusive mechanical deflection-based detection and restricted sampling rates, which hinder effective detection of high-frequency acoustic, ultrasonic, electric, and magnetic fields, as well as moisture changes, especially in long well applications.
Innovation Solution
The implementation of frequency multiplexing using multiple light sources with different frequency bands and a fiber optic cable with integrated actuation mechanisms, such as antennas and hydrophilic gels, to enhance sampling rates and detect a broad range of frequencies, including radio frequencies and ultrasonic signals, while also incorporating energy harvesting and storage for extended deployment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If mechanical deflection-based detection is used, then the sensor can detect acoustic signals, but the sampling rate is restricted and high-frequency detection is hindered
Solution Approach 1:
The patent segments the detection function into multiple independent actuation mechanisms (antenna for electromagnetic fields, hydrophilic gel for moisture) that can operate simultaneously with the optical fiber sensor, allowing parallel detection of different physical quantities at high sampling rates without mechanical deflection limitations
Solution Approach 2:
The optical fiber sensor system is enhanced with multi-functional actuation mechanisms that enable detection of multiple types of signals (acoustic, ultrasonic, electromagnetic, moisture) through a single integrated platform, overcoming the limitation of mechanical deflection-based detection while maintaining high sampling rates
2Productivity
If a single frequency light source is used, then the system is simple, but the bandwidth and sampling rate are limited
Solution Approach 1:
The patent employs a variable frequency light source that can dynamically adjust its frequency to match different detection requirements, enabling the system to optimize bandwidth and sampling rate for different signal types while maintaining manageable system complexity through controlled dynamic operation
Solution Approach 2:
The system changes the frequency parameter of the light source according to detection needs, allowing the optical fiber sensor to detect different frequency ranges (including high-frequency acoustic and ultrasonic signals) by adjusting the light frequency, thereby increasing bandwidth without proportionally increasing system complexity
3Duration of action of moving object
If temporary installation is used, then the system is flexible, but the operational lifetime is limited
Solution Approach 1:
The patent incorporates energy harvesting and storage capabilities that allow the sensor system to power itself autonomously, extending operational lifetime by eliminating dependence on external power sources while maintaining installation flexibility through self-powered operation
Solution Approach 2:
The system includes energy harvesting and storage components that provide more energy than immediately needed, allowing the sensor to operate for extended periods without external power, thereby extending operational lifetime while maintaining the flexibility of temporary installation
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 significantly increases the bandwidth and sampling rate of distributed acoustic sensors, enabling effective detection of high-frequency signals and moisture changes, and extends the system's operational lifetime by utilizing energy harvesting and storage, thereby overcoming the limitations of existing technologies.
Implementation Method 1
A variable-frequency light source is configured to emit a light beam and modulate a frequency of the light beam
Implementation Method 2
Acoustic detection using optical fibers exploits Rayleigh back-scattering along a fiber from a short pulse of light traversing the fiber
Implementation Method 3
The actuation mechanism includes an antenna configured to detect changes in an electromagnetic field
Implementation Method 4
The electromechanical transducer includes a piezoelectric element
Implementation Method 5
The actuation mechanism includes a hydrophilic gel configured to expand in the presence of moisture
Implementation Method 6
An energy harvesting device is configured to harvest energy from an ambient environment
Data Source
AI summary
A variable-frequency light source is configured to emit a light beam and modulate a frequency of the light beam. A fiber optic cable is attached to the variable frequency light source. The fiber optic cable is configured to receive the light beam at an inlet and pass the light beam to an exit. Multiple optical detectors are attached to the fiber optic cable. Each of the optical detectors is configured to detect a specified frequency of light that is backscattered through the fiber optic cable. An actuation mechanism is attached to the fiber optic cable. The actuation mechanism is configured to deform the fiber optic cable in response to a stimulus.