Magneto-Optic Fiber Bragg Grating Sensor
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Solution Overview
Problem
Existing optical fiber Bragg grating (FBG) sensors do not directly incorporate magnetic materials within the fiber to modify the optical wavelength in response to magnetic fields, relying instead on mechanical deformation for magnetic field sensing.
Innovation Solution
Incorporating ferromagnetic particles into the cladding of optical fiber Bragg grating sensors, allowing direct magneto-optic field coupling that changes the optical properties and reflected wavelength in response to magnetic fields.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If magnetic materials are attached to the external surface of optical fiber containing Bragg gratings, then magnetic field sensing capability is achieved through physical deformation, but the device complexity increases and measurement precision is limited by indirect transduction
Solution Approach 1:
The patent combines multiple functions into a single integrated structure by incorporating ferromagnetic particles directly into the optical fiber core or cladding during manufacturing. This merging eliminates the need for separate magnetic materials attached to the fiber surface, thereby reducing device complexity while maintaining magnetic field sensing capability. The ferromagnetic particles become an intrinsic part of the fiber structure, allowing direct magneto-optic interaction without mechanical deformation transduction.
Solution Approach 2:
The patent replaces the mechanical deformation-based sensing mechanism with a direct magneto-optic effect mechanism. Instead of using magnetic materials that physically deform the fiber to change the Bragg wavelength, ferromagnetic particles are embedded within the fiber to directly modulate the refractive index or optical properties through magnetic field interaction. This substitution eliminates the intermediate mechanical transduction step, improving measurement precision and reducing device complexity.
2Ease of manufacture
If ferromagnetic particles are incorporated directly within the optical fiber, then direct magneto-optic field coupling is achieved, but manufacturing precision requirements increase
Solution Approach 1:
The patent employs parameter changes in the manufacturing process to control the incorporation of ferromagnetic particles. By adjusting parameters such as particle concentration, size distribution, and embedding depth during fiber fabrication, the system achieves optimal magneto-optic coupling while maintaining manufacturability. The patent specifies that ferromagnetic particles should constitute 1-50% of the core or cladding material by volume, providing a flexible parameter range that balances manufacturing ease with sensing performance.
Solution Approach 2:
The patent creates composite optical fiber structures by combining standard optical fiber materials with ferromagnetic particles. This composite approach allows the use of well-established fiber manufacturing techniques while incorporating magnetic functionality. The ferromagnetic particles are integrated into the fiber matrix during the drawing process, creating a homogeneous composite structure that maintains the optical properties of the fiber while adding magneto-optic sensitivity.
3Adaptability or versatility
If standard optical fiber Bragg grating systems are used without magnetic material incorporation, then the system structure is simple, but the ability to directly sense magnetic fields through optical wavelength modification is lost
Solution Approach 1:
The patent enhances the universality of optical fiber Bragg grating systems by enabling them to perform multiple sensing functions. By incorporating ferromagnetic particles into the fiber, the system can simultaneously measure magnetic field strength, detect magnetic field direction, and maintain temperature and strain sensing capabilities. This multi-functionality is achieved without requiring fundamentally different sensor designs, allowing a single modified fiber structure to serve multiple sensing purposes.
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
Enables direct and measurable changes in the reflected wavelength of optical fiber Bragg grating sensors when exposed to magnetic fields, providing a more effective method for magnetic field sensing without mechanical transduction.
Implementation Method 1
direct magneto-optic field coupling in an optical fiber Bragg grating system
Data Source
AI summary
The invention is a magneto-optic coupled magnetic sensor that comprises a standard optical fiber Bragg grating system. The system includes an optical fiber with at least one Bragg grating therein. The optical fiber has at least an inner core and a cladding that surrounds the inner core. The optical fiber is part of an optical system that includes an interrogation device that provides a light wave through the optical fiber and a system to determine the change in the index of refraction of the optical fiber. The cladding of the optical fiber comprises at least a portion of which is made up of ferromagnetic particles so that the ferromagnetic particles are subject to the light wave provided by the interrogation system. When a magnetic field is present, the ferromagnetic particles change the optical properties of the sensor directly.