scholarly journals Suppression of Instability on Sensing Signal of Optical Pulse Correlation Measurement in Remote Fiber Sensing

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Hirokazu Kobayashi ◽  
Toshimasa Tsuzuki ◽  
Toshitake Onishi ◽  
Yuhei Masaoka ◽  
Xunjian Xu ◽  
...  
Keyword(s):  
Optical Fiber ◽  
Optical Pulse ◽  
Incident Light ◽  
Long Distance ◽  
Fiber Sensors ◽  
Fiber Sensing ◽  
Sensing System ◽  
Time Drift ◽  
Optical Fiber Sensing ◽  
Weak Points

Optical fiber sensing has the potential to overcome weak points of traditional electric sensors. Many types of optical fiber sensors have been proposed according to the modulation parameter of incident light. We have proposed an optical pulse correlation sensing system that focuses on the time drift values of the propagating optical pulses to monitor the temperature- or strain-induced extension along the optical fiber in the sensing region. In this study, we consider the instability in the optical pulse correlation sensing system applied to remote monitoring over a kilometer-long distance. We introduce a method to stabilize the instability of the pulse correlation signal resulting from the time drift fluctuation along a transmission line. By using this method, we can purify the response and improve the accuracy of signals at the focused sensing regions. We also experimentally demonstrate remote temperature monitoring over a 30 km-long distance using a remote reference technique, and we estimate the resolution and the measurable span of the temperature variation as(1.1/L)∘Cand(5.9×10/L)°C, respectively, whereLis the length of the fiber in the sensing region.

Distributed Raman Optical Fiber Sensing System Based on FPGA

2021 ◽  
Vol 58 (5) ◽  
pp. 0506006-506006142
Author(s):  
刘恒 Liu Heng ◽  
喻俊松 Yu Junsong ◽  
万生鹏 Wan Shengpeng ◽  
董德壮 Dong Dezhuang ◽  
熊新中 Xiong Xinzhong ◽  
...  
Keyword(s):  
Optical Fiber ◽  
Fiber Sensing ◽  
Sensing System ◽  
Optical Fiber Sensing

Structure optimization of gold-sputtered side-polished U-shaped plastic optical fiber SPR sensor

Sensor Review ◽  
2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Jianxing Jian Gu ◽  
Chen Yu ◽  
ZhenZe Yang ◽  
Peng Xue ◽  
Ning Jing ◽  
...  
Keyword(s):  
Optical Fiber ◽  
Conflicts Of Interest ◽  
Spectral Response ◽  
Plastic Optical Fiber ◽  
Fiber Sensors ◽  
Content Type ◽  
Sensor Optimization ◽  
Fiber Sensing ◽  
Optical Fiber Sensing ◽  
Practical Implications

Purpose This study aims to optimize the structure of gold-sputtered U-shaped plastic fiber sensors. Design/methodology/approach A group of U-shaped Au-sputtered plastic optical fiber sensing probes with polishing angles of 45°, 90° and 135° is prepared. Findings The experimental results show that the spectral response and sensitivity of the sensor at 45°polishing angle is twice that of the sensor at 90°. Research limitations/implications Due to the limitations of laboratory temperature and equipment, the overall effect has not reached the ideal, but the expected effect has been obvious. Experiments also optimize the sensor. Practical implications Optical fiber sensing has always been an indispensable part of various fields. Social implications Sensor optimization is of great help to the progress of technology and the development of science and technology. Originality/value The authors have no conflicts of interest to disclose.

scholarly journals Plastic Optical Fiber Sensing of Alcohol Concentration in Liquors

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Masayuki Morisawa ◽  
Shinzo Muto
Keyword(s):  
Optical Fiber ◽  
Fast Response ◽  
Alcohol Concentration ◽  
Novolac Resin ◽  
Sensor Head ◽  
Cladding Layer ◽  
Fiber Sensing ◽  
Sensing System ◽  
Green Led ◽  
Optical Fiber Sensing

A simple optical fiber sensing system of alcohol concentration in liquors has been studied. In this sensor head, a mixture polymer of novolac resin and polyvinylidenefluoride (PVDF) with a ratio of 9 : 1 was coated as a sensitive cladding layer on the plastic fiber core made of polystyrene-(PS-)coated polycarbonate (PC). Using this sensor head and a green LED light source, it was confirmed that alcohol concentration in several kinds of liquors from beer to whisky can easily be measured with a fast response time less than 1 minute.

scholarly journals Dynamic Responses Measured by Optical Fiber Sensor for Structural Health Monitoring

2019 ◽  
Vol 9 (15) ◽  
pp. 2956 ◽  
Author(s):  
Shiuh-Chuan Her ◽  
Shin-Chieh Chung
Keyword(s):  
Optical Fiber ◽  
Dynamic Strain ◽  
Fiber Grating ◽  
Base Excitation ◽  
Long Period ◽  
Fiber Sensing ◽  
Fbg Sensor ◽  
Sensing System ◽  
Optical Fiber Sensing ◽  
Period Fiber Grating

An optical fiber sensing system integrating a fiber Bragg grating (FBG) sensor, a long-period fiber grating (LPFG) optical filter and a photodetector is presented to monitor the dynamic response of a structure subjected to base excitation and impact loading. The FBG sensor is attached to a test specimen and connected to an LPFG filter. As the light reflected from the FBG sensor is transmitted through the long-period fiber grating filter, the intensity of the light is modulated by the wavelength, which is affected by the strain of the FBG. By measuring the intensity of the light using a photodetector, the wavelength reflected from the FBG sensor can be demodulated, thus leading to the determination of the strain in the structure. To demonstrate its effectiveness, the proposed sensing system was employed to measure the dynamic strain of a beam subjected to mechanical testing. The mechanical tests comprised three load scenarios: base excitation by a shaker at resonant frequency, impact loading by a hammer and shock test on a drop table. To monitor the dynamic strain during the test and validate the accuracy of the measurement of the FBG sensor, strain gauge was used as reference. Experimental results show good correlation between the measurements of FBG sensor and strain gauge. The present work provides a fast response and easy-to-implement optical fiber sensing system for structural health monitoring based on real-time dynamic strain measurements.

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