Dynamic Fiber Bragg Grating Interrogation System
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing high frequency vibration measurement technologies, such as fiber Bragg grating (FBG) interrogation systems, are limited by the need for specialized components like scanning optical filters, which increase costs and complexity, and struggle to accurately measure dynamic signals without additional equipment for multiplexing.
Innovation Solution
A dynamic FBG interrogation system using two wavelength-matched FBGs and a photodiode, where the first FBG attenuates the central wavelength in the transmission spectrum, allowing the second FBG to reflect a signal that is detected by a photodiode, enabling high frequency vibration measurement without specialized filters or additional equipment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If scanning optical filters are used for FBG interrogation, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The patent extracts the filtering function from separate scanning optical filters and integrates it directly into the FBG structure itself. By using the FBG's inherent spectral filtering properties, the system eliminates the need for external scanning filters while maintaining measurement precision.
Solution Approach 2:
The FBG serves multiple functions simultaneously: it acts as both the sensing element and the optical filter. This multi-functionality reduces the number of separate components needed in the system, thereby reducing complexity while maintaining measurement capabilities.
2Measurement precision
If specialized optical filters are used for high frequency interrogation, then measurement precision is improved, but cost increases
Solution Approach 1:
The patent removes the need for expensive specialized optical filters by utilizing the FBG's intrinsic spectral characteristics. This extraction of the filtering function from separate components directly reduces system cost while maintaining measurement precision.
Solution Approach 2:
The patent uses standard, commercially available FBGs instead of expensive specialized filters. These standard FBGs are cost-effective and can be easily replaced if needed, reducing the overall system cost while maintaining performance.
3Adaptability or versatility
If additional equipment for multiplexing is added, then adaptability is improved, but device complexity increases
Solution Approach 1:
The patent segments the optical signal into different wavelength components that can be independently detected. By using multiple FBGs with different central wavelengths, the system achieves multiplexing capability without requiring complex additional equipment, as each FBG operates independently at its specific wavelength.
Data Source
AI summary
A fiber Bragg grating (FBG) interrogation method allows for high frequency dynamic measurement. The method may utilize a broad band light source connected to the sensing elements. Each sensing element may comprise two wavelength matching FBGs, a coupler, and a photodiode. The FBG closest to the light source may attenuate the central wavelength in the transmission spectrum and thus the reflection spectrum of the second FBG. Variations in intensity of the second FBG may be measured by the photodiode and can be calibrated to the desired measurands.