Research on joint measurement system of optical fiber Brillouin temperature and strain distribution
In the field of optical fiber sensing technology, optical fiber Brillouin temperature sensor and optical fiber strain sensor are two common sensor types. This paper proposes a design scheme of a joint measurement system of optical fiber Brillouin temperature sensor and optical fiber strain sensor, and uses MATLAB to realize the data processing and analysis of the system.
- System Design
The system mainly consists of the following components:
- Light source: Generally, a laser or LED is used as a light source, and an optical signal with a wavelength of about 1550nm is emitted.
- Optical fiber: The optical fiber transmits the signal, one of which is used as a test fiber and the other is used as a reference.
- Spectrometer: used to collect reflection spectra of test fiber and reference fiber.
- Signal processing module: Process and analyze the collected signals to obtain temperature and strain distribution information.
- Data Processing and Analysis
2.1 Optical fiber Brillouin temperature sensor
In the fiber optic Brillouin temperature sensor, by collecting the reflection spectrum of the test fiber and the reference fiber, calculating the difference between the two, the Brillouin frequency shift information is obtained, and the temperature distribution information is further calculated.
The specific operation steps are as follows:
- Perform spectral measurements on the test fiber and reference fiber to obtain reflection spectrum data.
- The spectral data is processed by MATLAB to obtain the reflectivity of the test fiber and the reference fiber.
- Calculate the reflectance difference between the test fiber and the reference fiber, and obtain the temperature distribution information through the Brillouin frequency shift formula.
2.2 Optical fiber strain sensor
In the fiber optic strain sensor, the reflection spectra of the test fiber and the reference fiber are also collected, but the strain state of the fiber is measured at this time. According to the Brillouin frequency shift change caused by the fiber length and strain, the fiber strain value can be calculated.
The specific operation steps are as follows:
- Perform spectral measurements on the test fiber and reference fiber to obtain reflection spectrum data.
- via MATLAB for