- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Concrete Crack Monitoring Using a Novel Strain Transfer Model for Distributed Fiber Optics Sensors
摘要： In this paper, we study the strain transfer mechanism between a host material and an optical fiber. A new analytical model handling imperfect bonding between layers is proposed. A general expression of the crack-induced strain transfer from fractured concrete material to optical fiber is established in the case of a multilayer system. This new strain transfer model is examined through performing wedge splitting tests on concrete specimens instrumented with embedded and surface-mounted fiber optic cables. The experimental results showed the validity of the crack-induced strain expression fitted to the distributed strains measured using an Optical Backscattering Reflectometry (OBR) system. As a result, precise estimations of the crack openings next to the optical cable location were achieved, as well as the monitoring of the optical cable response through following the strain lag parameter.
关键词： crack,distributed strains,crack opening,wedge splitting test,fiber optics sensors,strain transfer,imperfect bonding,concrete
更新于2025-09-23 15:19:57
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Design of long period fiber grating surrounding refractive index sensor based on mode transition near phase-matching turning point
摘要： This work presents a novel design of long period fiber grating (LPFG) refractive index sensor based on mode transition near phase-matching turning point (PMTP). The dual peaks can approach to PMTP by adjusting the fiber radius, and LPFG can operate in the mode transition range by choosing the optimal film thickness. Through experiments, the LPFG based on mode transition near PMTP was fabricated by the aforesaid design, and a glycerol solution concentration monitoring test was performed to analyze its sensing properties. The results show that if the dual peaks are close to PMTP and the overlay thickness stays within the mode transition range, the sensitivity to surrounding refractive index (SRI) will be greatly improved. Compared with the regular LPFG sensors based on dual peaks resonance or the LPFG sensors based on mode transition, this LPFG has a higher sensitivity to SRI which can reach to 4900nm/RIU in the SRI range of 1.34~1.39.
关键词： Fiber optics,Thin films,Fiber optics sensors
更新于2025-09-19 17:15:36
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Cascaded tilted fiber Bragg grating for enhanced refractive index sensing
摘要： We proposed and experimentally demonstrated a cascaded tilted fiber Bragg grating (TFBG) for enhanced refractive index sensing. The TFBG is UV-inscribed in series in ordinary single-mode fiber (SMF) and reduced-diameter SMF with the same tilt angle, and then excites two sets of superposed spectral combs of cladding modes. The cascaded TFBG with total length of 18 mm has a much wider wavelength range over 100 nm and narrower wavelength separation than that of a TFBG only in the SMF, enabling an enlarged range and a higher accuracy of refractive index measurement. The fabricated TFBG with the merits of enhanced sensing capability and temperature self-calibration presents great potentials in the biochemical sensing applications.
关键词： refractive index measurement,tilted fiber Bragg grating,fiber optics sensors
更新于2025-09-19 17:15:36
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[OSA Optical Fiber Sensors - Lausanne (2018..-..)] 26th International Conference on Optical Fiber Sensors - Distributed hydrogen monitoring with phase-sensitive optical time-domain reflectometry
摘要： We propose a distributed hydrogen sensing system based on ?-OTDR and a novel coating configuration with fiber adhesively bonding to palladium foils. An ultra-high sensitive distributed hydrogen sensing with 5 cm spatial resolution is demonstrated.
关键词： Chemical analysis,Scattering, Rayleigh,Fiber optics sensors,Fiber optics
更新于2025-09-19 17:13:59
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[OSA Optical Fiber Sensors - Lausanne (2018..-..)] 26th International Conference on Optical Fiber Sensors - Label-free distributed hydrogen sensing with stimulated Raman scattering in hollow-core fibers
摘要： We present the first experimental demonstration of distributed hydrogen sensing using stimulated Raman scattering in gas-filled hollow-core photonic crystal fibers. The system performances in terms of sensitivity, selectivity, dynamic range and sensing distance are discussed.
关键词： Fiber optics,Spectroscopy,Fiber optics sensors,Spectroscopy, Raman,Photonic crystal fibers
更新于2025-09-19 17:13:59
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[IEEE 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Huangshan, China (2019.8.5-2019.8.8)] 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Construction of Mach-Zehnder interferometer in no-core fiber using single straight in-fiber waveguide
摘要： We demonstrated a new fiber in-line Mach-Zehnder interferometer in no-core fiber based on single straight waveguide fabricated by femtosecond laser. The device is simple in structure and fabrication and is robust, and can be used for high temperature and bend sensing, with the sensitivity of of -278.86 pm/°C and 0.28nm/m-1, respectively. Moreover, the free spectral range of the interferometer device can be easily controlled and in a precise manner.
关键词： Fiber optics sensors,Fiber optics components
更新于2025-09-16 10:30:52
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[OSA Optical Fiber Sensors - Lausanne (2018..-..)] 26th International Conference on Optical Fiber Sensors - Fully distributed pressure sensing with ultra-high-sensitivity using side-hole fibers
摘要： A highly sensitive distributed pressure sensing system (< 20 hPa) based on phase sensitive optical time-domain reflectometry with side air holes fiber is proposed, reaching a sensing range of 1.05 km with a 5 cm spatial resolution.
关键词： Pressure measurement,Scattering, Rayleigh,Fiber optics sensors,Fiber optics
更新于2025-09-16 10:30:52
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[IEEE 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Huangshan, China (2019.8.5-2019.8.8)] 2019 18th International Conference on Optical Communications and Networks (ICOCN) - An MMF-NCF-MMF Structure Based SPR Sensor for Highly Sensitive Detection of Glucose and Salt Solutions
摘要： An optic-fiber SPR sensor based on no-core fiber (NCF) is presented and available for microfluidic chip. Our sensor has advantages of high sensitivity (3094 nm / RIU), wide RI range (1.333-1.405) and compactness.
关键词： Fiber optics sensors,No-core fiber,Surface plasmon
更新于2025-09-16 10:30:52
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Liquid-Crystal-Filled Side-hole Fiber for High-Sensitivity Temperature and Electric Field Measurement
摘要： We propose a highly sensitive sensor based on a nematic liquid-crystal-filled side-hole fiber. The liquid crystal is precisely filled into an air hole of the optical fiber using a method of manually gluing in the fusion splicer. Due to the coupling between the liquid crystal waveguide and the fiber core, multiple response dips appear in the transmission spectrum of the device. When an external temperature or electric field variation is applied to the liquid crystal and its refractive index changes, the transmission spectrum of this device will shift accordingly. Temperature and electric field response tests were performed on the device in the experiment, and the obtained temperature and electric field sensitivities were as high as ?1.5 nm/°C and 3.88 nm/Vpp, respectively. For the exhibited advantages of being easy to manufacture, low cost, and high sensitivity, the proposed sensor is very promising for actual application in temperature or weak electric field monitoring.
关键词： liquid crystal,side-hole fiber,fiber optics sensors
更新于2025-09-16 10:30:52
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High-resolution temperature sensor based on intracavity sensing of fiber ring laser
摘要： The principle and design of high-resolution sensors are of great significance in the development of fiber-optic sensors. In this paper, a general method based on intracavity sensing of fiber ring laser (FRL) for high-resolution measurement, and a high-resolution temperature sensing system is experimentally demonstrated. The theoretical model for intracavity sensing of FRL is presented. In the sensing system, a fiber-optic Sagnac loop is inserted into an FRL for temperature measurement, which performs as the filter and sensing head simultaneously. Because the filter characteristics of the Sagnac loop is modulated by temperature, the intracavity intensity-modulated sensing is induced for the output power of the FRL. With the method based on intracavity sensing, the temperature resolution level of the sensing system has been improved from 10-3 °C to 10-6 °C. The stability and measurement errors are also measured. The proposed method can be extensible to similar fiber-optic sensors to improve measurement resolution.
关键词： Fiber optics sensors,fiber lasers,high resolution
更新于2025-09-16 10:30:52