scholarly journals A Highly Sensitive and Miniature Optical Fiber Sensor for Electromagnetic Pulse Fields

Sensors ◽  
2021 ◽  
Vol 21 (23) ◽  
pp. 8137
Author(s):  
Min Zhao ◽  
Xing Zhou ◽  
Yazhou Chen

The detection of an electromagnetic pulse (EMP) field is of great significance in determining the field environment of tested equipment in small spaces. Finger-shaped miniature optical fiber sensors for electromagnetic pulse field measurement were designed. The antenna of a weak field sensor was integrated with a shielding shell, and the wire welded at the direct electro-optic converting circuit connected to an optical fiber through special structure and circuit design was taken as the antenna of a strong field sensor. Measurements in the time domain and frequency domain had been carried out for the two sensors. Experiment results demonstrate that the weak field sensor and the strong field sensor have flat responses from 100 kHz to 1 GHz with a variation of 2.3 dB and 2.9 dB, respectively, and the EMP waveform detected by the sensors agrees well with the applied standard square wave. Moreover, the strong field sensor exhibits linear responses from 645 V/m to 83 kV/m. The resolution of the weak field sensor is as low as 13 V/m. The result indicated that the designed sensors had good performance.

1997 ◽  
Vol 503 ◽  
Author(s):  
F. Ansari ◽  
Z. Chen ◽  
Q. Li

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.


1997 ◽  
Vol 503 ◽  
Author(s):  
F. Ansari

ABSTRACTIt is possible to monitor the initiation and progress of various mechanical or environmentally induced perturbations in concrete elements by way of fully integrated optical fiber sensors. Geometric adaptability and ease by which optical fibers can be embedded within concrete elements has led to the development of a number of innovative applications for concrete elements. This article is intended for a brief introduction into the theories, principles, and applications of fiber optic sensors as they pertain to applications in concrete.. However, due to the fact that the transduction mechanism in optical fibers is invariant of the materials employed, the principles introduced here also correspond to other structural materials. The only application related differences among various materials pertain to sensitivity and choice of optical fiber sensor types.


2011 ◽  
Vol 121-126 ◽  
pp. 4166-4170
Author(s):  
Shiuh Chuan Her ◽  
Chang Yu Tsai

Optical fiber sensors with light weight, small size and immunity to electromagnetic interference have been found to be a promising device for use in the development of smart structures. It is well known that the strain transfer from the host structure to the optical fiber sensor is dependent on the bonding characteristics such as adhesive layer and bonded length. In this investigation, the optical fiber sensor is surface bonded on the host structure. A theoretical model consisting of the optical fiber, adhesive layer and host material, is proposed to determine the strain in the optical fiber sensor induced by the host structure. The theoretical predictions were validated with the numerical analysis using the finite element method.


Sensors ◽  
2021 ◽  
Vol 21 (22) ◽  
pp. 7514
Author(s):  
Aldo Minardo ◽  
Luigi Zeni ◽  
Agnese Coscetta ◽  
Ester Catalano ◽  
Giovanni Zeni ◽  
...  

We report the experimental application of distributed optical fiber sensors, based on stimulated Brillouin scattering (SBS), to the monitoring of a small-scale granular slope reconstituted in an instrumented flume and subjected to artificial rainfall until failure, and to the monitoring of a volcanic rock slope. The experiments demonstrate the sensors’ ability to reveal the sudden increase in soil strain that foreruns the failure in a debris flow phenomenon, as well as to monitor the fractures in the tuff rocks. This study offers an important perspective on the use of distributed optical fiber sensors in the setting up of early warning systems for landslides in both rock and unconsolidated materials.


2021 ◽  
Vol 22 ◽  
pp. 48
Author(s):  
Yujie Li ◽  
Ming Zhang ◽  
Yu Zhu

This paper proposes a POI displacement estimation method based on the functional optical fiber sensor and the phase modulation principle to improve the POI displacement estimation accuracy. First, the relation between the object deformation and the optic fiber lightwave phase is explained; the measurement principle of functional optical fiber sensor based on the heterodyne interference principle and its layout optimization method is proposed, and a POI displacement estimation model is presented based on the data approach. Secondly, a beam is taken as the simulation object, the optimal position and length of the optical fiber sensor are determined based on its simulation data. Finally, the experimental device is designed to verify the effectiveness of the POI displacement estimation method based on the optic fiber sensors. The frequency-domain plot of the signals shows that the optical fiber sensors can express the flexible deformation of the analyzed object well. The POI displacement estimation model with the fiber optic sensor signals as one of the inputs is constructed. Through estimating the test data, the error using the optical fiber sensor-based POI displacement estimation method proposed in this paper reduces by more than 61% compared to the rigid body-based assumption estimation method.


2011 ◽  
Vol 467-469 ◽  
pp. 279-282
Author(s):  
Shiuh Chuan Her ◽  
Chang Yu Tsai

Optical fiber sensors with light weight, small dimension and immunity to electromagnetic interference are widely used in structural health monitoring device. In this investigation, a theoretical model of the strain transferred from the host material to the embedded optical fiber is developed to reveal the differential strains between the optical fiber sensor and host material. The theoretical predictions are validated with the numerical analysis using the finite element method. The percentage of strain in the host material actually transferred to the optical fiber is dependent on the bonding characteristics such as adhesive layer, protective coating and host material. Parametric study shows that the larger of the host material the more strain is transferred to the optical fiber.


2005 ◽  
Vol 297-300 ◽  
pp. 659-664
Author(s):  
Hideaki Murayama ◽  
Kazuro Kageyama ◽  
Isamu Ohsawa ◽  
Makoto Kanai ◽  
Kiyhoshi Uzawa ◽  
...  

We have developed a novel fiber-optic vibration sensors and applied commercially available strain and temperature sensors to health monitoring of composite structures. In this study, we constructed an optical fiber network integrating four types of optical fiber sensor into a carbon reinforced plastic (CFRP) panel. These four sensors were the vibration sensor developed by our laboratory, two distributed sensors based on Brillouin and Raman backscattering and Fiber Bragg Grating (FBG) sensors. By dealing the data obtained from the measurement systems corresponding to these four sensors, strain/stress and temperature distributions throughout the panel can be monitored. Vibration and elastic waves transmitting on the panel are also detected at several sensing points. Furthermore, we will be able to determine damage locations and modes by processing the wave signals. To make the panel with the optical fiber sensor network more sensitive and smarter, we are developing some techniques that can improve the performance of the sensors and can assess the structural integrity by analyzing measurement results. In this paper, the development of the first generation of our smart composite panel with the optical fiber sensors is described and the techniques making the panel more sensitive and smarter are also described.


2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Yani Zheng ◽  
Gaurav Dhiman ◽  
Ashutosh Sharma ◽  
Amit Sharma ◽  
Mohd Asif Shah

The usage of wireless sensors has become widespread for the collection of data for various Internet of Things (IoT) products. Specific wireless sensors use optical fiber technology as transmission media and lightwave signals as carriers, showing the advantages of antielectromagnetic interference, high sensitivity, and strong reliability. Hence, their application in IoT systems becomes a research hotspot. In this article, multiple optical fiber sensors are constructed as an IoT detection system, and a Transmission Control Protocol (TCP)/Internet Protocol (IP) communication stack is used for the sensor module. Furthermore, design of gateway module, data server, and monitoring module is established in order to run the data server in the Windows system and communicate across the network segments. Furthermore, the optical fiber sensor is connected to the development board with WiFi, meanwhile considering the optical fiber wireless network’s congestion problem. The fuzzy logic concept is introduced from the perspective of cache occupancy, and a fiber sensor’s network congestion control algorithm is proposed. In the experiment, the IoT detection system with multiple optical fiber sensors is used for water level detection, and the sensor’s real-time data detected by the User Interface (UI) are consistent with the feedback results. The proposed method is also compared with the SenTCP algorithm and the CODA algorithm, and it was observed that the proposed network congestion control algorithm based on the fuzzy logic can improve network throughput and reduce the network data packet loss.


2020 ◽  
Vol 8 ◽  
Author(s):  
Yi Cai ◽  
Ming Li ◽  
Minghao Wang ◽  
Jin Li ◽  
Ya-nan Zhang ◽  
...  

Recently, novel fluorescent probes based on biomaterials and luminescent nanomaterials for metal ions attract tremendous attentions, owing to their advantages of simple operation, high sensitivity and rapid response for metals detection. Immobilized on the optical fiber sensor, fluorescent probes reveal the advantages while facing outdoor detection challenges. Therefore, numerous fluorescent optical fiber sensors for metal ions have been developed for online and in-situ detection to predict and prevent the environmental problems. Differ from refractometer-based fiber sensors, the structures of the fiber sensors based on fluorescent materials are usually simple, and the characters of the materials and the fabrication processes of fiber sensors are more significant to the sensing performances. This paper summarized the studies of optical fiber sensors for metal detection based on novel fluorescent materials to help researchers get the highlights of recent notable advancements and obtain the better potential prospects.


2014 ◽  
Vol 530-531 ◽  
pp. 3-6
Author(s):  
Shinn Fwu Wang ◽  
Ming Jen Wang ◽  
Jyh Shyan Chiu

In this paper, a long cylindrical multimode optical fiber sensor (OFS) based on multiple total internal reflections in heterodyne interferometry is proposed. The cladding of the sensing portions of the fiber sensors is removed, but dont be coated with any metal films. With the OFS the phase shift difference due to the multiple total internal reflections (MTIRs) effect between the p-and s-polarizations can be measured by using the heterodyne interferometry. Substituting the phase shift difference into Fresnels equations, the refractive index for the tested medium can be calculated. According to numerical simulations and experimental results, the long cylindrical OFS is with the best resolution of 0.0000028 refractive index unit (RIU). However, the OFS could be valuable for chemical, biological and biochemical sensing. It has some merits, such as, high sensitivity, high resolution, stability, small size and in real-time measurement.


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