Graphene-controlled fiber Bragg grating and enabled optical bistability

2016 ◽  
Vol 41 (3) ◽  
pp. 603 ◽  
Author(s):  
Xuetao Gan ◽  
Yadong Wang ◽  
Fanlu Zhang ◽  
Chenyang Zhao ◽  
Biqiang Jiang ◽  
...  
Keyword(s):  
Fiber Bragg Grating ◽  
Optical Bistability ◽  
Bragg Grating

Bistability of ultrashort pulses in FBG under different nonlinearity profiles

2017 ◽  
Vol 26 (02) ◽  
pp. 1750022 ◽  
Author(s):  
P. V. F. Pinto ◽  
T. M. Pessoa ◽  
J. M. Jacinto ◽  
J. C. Sales ◽  
A. C. Ferreira ◽  
...  
Keyword(s):  
Band Gap ◽  
Fiber Bragg Grating ◽  
Optical Switching ◽  
Optical Bistability ◽  
Photonic Band Gap ◽  
Ultrashort Pulses ◽  
Nonlinear Regime ◽  
Bragg Grating ◽  
Linear Quadratic ◽  
Photonic Band

In this work, we studied the optical bistability of Fiber Bragg Grating (FBG) under nonlinear regime, considering three increasing and decreasing profiles of nonlinearity: linear, quadratic and exponential. We varied the nonlinearity range in each profile, and obtained different curves of bistability and reflectivity. We analyzed the powers [Formula: see text] and [Formula: see text], as well as the width of the photonic band gap ([Formula: see text] of each device under different nonlinearity profiles, and we observed the changes in reflectivity of the FBG. The power intensities [Formula: see text] and [Formula: see text] obtained for the bistability of decreasing profiles were lower than those obtained for the increasing profiles, and the values of [Formula: see text] were also lower in decreasing profiles, which is useful for optical switching applications.

scholarly journals Experimental Strain Measurement Approach Using Fiber Bragg Grating Sensors for Monitoring of Railway Switches and Crossings

Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3639
Author(s):  
Abdelfateh Kerrouche ◽  
Taoufik Najeh ◽  
Pablo Jaen-Sola
Keyword(s):  
Fiber Bragg Grating ◽  
Experimental Tests ◽  
Cost Effective ◽  
Measuring Method ◽  
Bragg Grating ◽  
Railway Network ◽  
System Failures ◽  
Railway Infrastructure ◽  
Train Speed ◽  
And Control

Railway infrastructure plays a major role in providing the most cost-effective way to transport freight and passengers. The increase in train speed, traffic growth, heavier axles, and harsh environments make railway assets susceptible to degradation and failure. Railway switches and crossings (S&C) are a key element in any railway network, providing flexible traffic for trains to switch between tracks (through or turnout direction). S&C systems have complex structures, with many components, such as crossing parts, frogs, switchblades, and point machines. Many technologies (e.g., electrical, mechanical, and electronic devices) are used to operate and control S&C. These S&C systems are subject to failures and malfunctions that can cause delays, traffic disruptions, and even deadly accidents. Suitable field-based monitoring techniques to deal with fault detection in railway S&C systems are sought after. Wear is the major cause of S&C system failures. A novel measuring method to monitor excessive wear on the frog, as part of S&C, based on fiber Bragg grating (FBG) optical fiber sensors, is discussed in this paper. The developed solution is based on FBG sensors measuring the strain profile of the frog of S&C to determine wear size. A numerical model of a 3D prototype was developed through the finite element method, to define loading testing conditions, as well as for comparison with experimental tests. The sensors were examined under periodic and controlled loading tests. Results of this pilot study, based on simulation and laboratory tests, have shown a correlation for the static load. It was shown that the results of the experimental and the numerical studies were in good agreement.

A Fiber Bragg Grating acceleration sensor with temperature compensation

Optik ◽  
2021 ◽  
pp. 166993
Author(s):  
Xianfeng Zhao ◽  
Zhen’an Jia ◽  
Wei Fan ◽  
Wangfei Liu ◽  
Hong Gao ◽  
...  
Keyword(s):  
Fiber Bragg Grating ◽  
Temperature Compensation ◽  
Bragg Grating ◽  
Acceleration Sensor
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