Optical fiber sensor interrogation improved by active fiber loop

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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A Study on Thermal Detection Based on Support Vector Machine Using Dynamic Time Warping and Warping and Application to Optical Fiber Sensor

IEEE Sensors Journal ◽

10.1109/jsen.2020.3036460 ◽

2020 ◽

pp. 1-1

Author(s):

Osamu Furukawa

Keyword(s):

Support Vector Machine ◽

Optical Fiber ◽

Dynamic Time Warping ◽

Optical Fiber Sensor ◽

Fiber Sensor ◽

Support Vector ◽

Time Warping ◽

Thermal Detection ◽

Dynamic Time

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Design and validation of fiber optic localized surface plasmon resonance sensor for thyroglobulin immunoassay with high sensitivity and rapid detection

Scientific Reports ◽

10.1038/s41598-021-95375-y ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Hyeong-Min Kim ◽

Dae Hong Jeong ◽

Ho-Young Lee ◽

Jae-Hyoung Park ◽

Seung-Ki Lee

Keyword(s):

Surface Plasmon Resonance ◽

Optical Fiber ◽

Surface Plasmon ◽

Plasmon Resonance ◽

Localized Surface Plasmon Resonance ◽

Optical Fiber Sensor ◽

Fiber Sensor ◽

Localized Surface Plasmon ◽

Simple Method ◽

Resonance Sensor

AbstractA simple optical fiber sensor based on localized surface plasmon resonance was constructed for direct and rapid measurement of thyroglobulin (Tg). Specific tests for Tg in patients that have undergone thyroidectomy are limited because of insufficient sensitivity, complicated procedures, and in some cases, a long time to yield a result. A sensitive, fast, and simple method is necessary to relieve the psychological and physical burden of the patient. Various concentrations of Tg were measured in a microfluidic channel using an optical fiber sensor with gold nanoparticles. The sensor chip has a detection limit of 93.11 fg/mL with no specificity for other antigens. The potential applicability of the Tg sensing system was evaluated using arbitrary samples containing specific concentrations of Tg. Finally, the sensor can be employed to detect Tg in the patient’s serum, with a good correlation when compared with the commercial kit.

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Design of self-heating test platform for sulfide corrosion and oxidation based on Fuzzy PID temperature control system

Measurement and Control ◽

10.1177/00202940211020338 ◽

2021 ◽

pp. 002029402110203

Author(s):

Cheng-Wei Chu ◽

Zhi-Chao Zhu ◽

Hai-Tao Bian ◽

Jun-Cheng Jiang

Keyword(s):

Control System ◽

Optical Fiber ◽

Temperature Control ◽

Optical Fiber Sensor ◽

Oxidation Temperature ◽

Fiber Sensor ◽

Fuzzy Pid ◽

Test Platform ◽

Sulfide Corrosion ◽

Corrosion And Oxidation

In this paper, the changes of oxidation temperature of sulfide corrosion and the deficiency of distributed optical fiber application were analyzed. The test platform of oxidation temperature of sulfide corrosion was established, and the performance test of optical fiber and the simulation of oxidation temperature of sulfide corrosion were realized. The hardware part of the control system used STM32 as the controller, the software part was based on the process characteristics of the controlled object, using MATLAB to carry out the simulation of PID, fuzzy, fuzzy PD plus I, fuzzy PID algorithms, and their performance are evaluated using both single indexes and comprehensive indexes. The experimental results also showed that the proposed fuzzy PID can achieve better control performance with less overshoot and shorter setting time. Therefore, the fuzzy PID was chosen as the temperature control algorithm to build the optical fiber sensor test platform, and an alarm method for testing the oxidation temperature of large area sulfide corrosion based on the optical fiber performance was obtained. Then, considering the influence of spatial resolution on optical fiber sensor, this paper used piecewise PID to simulate the temperature rise process of three stages of sulfurization corrosion and oxidation. The results showed that the alarm method of oxidation temperature of sulfurization corrosion has limitations for small-scale oxidation of sulfurization corrosion, and it needed to be combined with machine learning to identify temperature anomaly.

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A Multiplexed Optical Fiber Sensor System For Distributed Measurement Of Structural Strains

MRS Proceedings ◽

10.1557/proc-503-119 ◽

1997 ◽

Vol 503 ◽

Author(s):

F. Ansari ◽

Z. Chen ◽

Q. Li

Keyword(s):

Optical Fiber ◽

Optical Switch ◽

Optical Fiber Sensor ◽

Fiber Material ◽

Smart Structure ◽

Sensor System ◽

Fiber Sensor ◽

Fiber Sensors ◽

Large Structures ◽

Distributed Measurement

ABSTRACTStructurally integrated optical fiber sensors form the basis for smart structure technology. Over the past decade a variety of sensor configurations have been developed for measurement of strains and deformations in structures. Strains and deformations alter the refractive index and the geometry of the optical fiber material. These changes perturb the intensity, phase, and polarization of the light-wave propagating along the probing fiber. The optical perturbations are detected for the determination of strain. The research presented here describes the development of a new optical fiber sensor system for measurement of structural strains based on white light interferometry. An optical switch provides for multiplexing of strain signals from various locations in the structure. Redundant Bragg grating type fiber optic sensors as well as strain gauges were employed for comparison and verification of strain signals as measured by the new system. The system provides capability for distributed sensing of strains in large structures.

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