High fringe visibility fiber sensor based on MMF-FCF-MMF structure for dual-parameter detection

ABSTRACT The coherent-dispersion spectrometer (CODES) is a new exoplanet detection instrument using the radial velocity (RV) method. This attempts mainly to improve environmental sensitivity and energy utilization by using an asymmetric, common-path Sagnac interferometer instead of a traditional Michelson interferometer. In order to verify its feasibility and to choose the appropriate key parameters to obtain the optimal performance, research on data processing for the design stage of the CODES is performed by systematic simulation and analysis. First, the instrument modelling is carried out for further data analysis according to the principle of the CODES, and the reliability of the model is verified by experiments. Second, the influence of key parameters on fringe visibility is analysed systematically, which provides a certain reference for the choice of the key parameters. Third, the RV inversion method for the CODES is proposed and optimized according to the related analysis results so as to promote RV inversion precision. Finally, the recommended values for the key parameters of the CODES are given. The experimental results show that the data processing error of RV inversion is less than 0.6 m s–1 within the recommended range of key parameters. This indicates that the scheme of the CODES is reasonable and feasible, and that the proposed data processing method is effective and well matched with the instrument design.

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Transformer Insulation Paper Moisture Measurement Using Optical Fiber Sensor

2020 IEEE Region 10 Symposium (TENSYMP) ◽

10.1109/tensymp50017.2020.9230830 ◽

2020 ◽

Author(s):

Deba Kumar Mahanta

Keyword(s):

Optical Fiber ◽

Optical Fiber Sensor ◽

Fiber Sensor ◽

Moisture Measurement ◽

Transformer Insulation

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Measurement Improvement of Distributed Optical Fiber Sensor via Lorenz Local Single Peak Fitting Algorithm

Symmetry ◽

10.3390/sym13071166 ◽

2021 ◽

Vol 13 (7) ◽

pp. 1166

Author(s):

Bin Liu ◽

Jianping He ◽

Shihai Zhang ◽

Yinping Zhang ◽

Jianan Yu ◽

...

Keyword(s):

Optical Fiber ◽

Frequency Shift ◽

Optical Fiber Sensor ◽

Gain Spectrum ◽

Fiber Sensor ◽

Peak Fitting ◽

Fitting Algorithm ◽

Distributed Optical Fiber Sensor ◽

Brillouin Gain ◽

Distributed Optical Fiber

Brillouin frequency shift (BFS) of distributed optical fiber sensor is extracted from the Brillouin gain spectrum (BGS), which is often characterized by Lorenz type. However, in the case of complex stress and optical fiber self damage, the BGS will deviate from Lorenz type and be asymmetric, which leads to the extraction error of BFS. In order to enhance the extraction accuracy of BFS, the Lorenz local single peak fitting algorithm was developed to fit the Brillouin gain spectrum curve, which can make the BSG symmetrical with respect to the Brillouin center frequency shift. One temperature test of a fiber-reinforced polymer (FRP) packaged sensor whose BSG curve is asymmetric was conducted to verify the idea. The results show that the local region curve of BSG processed by the developed algorithm has good symmetry, and the temperature measurement accuracy obtained by the developed algorithm is higher than that directly measured by demodulation equipment. Comparison with the reference temperature, the relative measurement error measured by the developed algorithm and BOTDA are within 4% and 8%, respectively.

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