scholarly journals Determination of Wavelength Shift of Fiber Bragg Grating Sensors by Tunable Single-mode Diode Laser

2013 ◽  
Vol 23 (1) ◽  
pp. 75
Author(s):  
Nguyen The Anh ◽  
Pham Thanh Son ◽  
Nguyen Thuy Van ◽  
Hoang Thi Hong Cam ◽  
Ngo Quang Minh ◽  
...  
Keyword(s):  
Fiber Bragg Grating ◽  
Low Cost ◽  
Broad Band ◽  
Single Mode ◽  
Bragg Grating ◽  
Wavelength Shift ◽  
Physical Parameters ◽  
Lasing Wavelength ◽  
Dfb Laser

We propose a novel principle of determination of fiber Bragg grating (FBG) wavelength shift which is impacted by a variation of physical parameters such as temperature, pressure and/or strain. In common case the wavelength shift of FBG was monitored by wavelength measurement using a high-cost spectrometer and a broad band light source. In our proposed technique the wavelength shift of FBG can be determined by change of lasing wavelength of distributed feedback laser (DFB-laser) due to the change of laser substrate temperature. The maximal opto-electrical intensity of photodetector would be obtained when the laser wavelength and FBG reflection wavelength are coincided. The FBG sensor prototype has shown excellent response for laser temperature change in the range of \(10^{\circ}C-50^{\circ}C\) with the ratio \(\Delta \lambda /\Delta T\) of the DFB laser is of 77.5 pm.K\(^{ - 1}\). Key features of the proposed technique are fabrication of low-cost FBG sensors for civil engineering.

scholarly journals Femtosecond-Laser-Assisted Fabrication of Radiation-Resistant Fiber Bragg Grating Sensors

2022 ◽  
Vol 12 (2) ◽  
pp. 886
Author(s):  
Hun-Kook Choi ◽  
Young-Jun Jung ◽  
Bong-Ahn Yu ◽  
Jae-Hee Sung ◽  
Ik-Bu Sohn ◽  
...  
Keyword(s):  
Femtosecond Laser ◽  
Fiber Bragg Grating ◽  
Optical Fibers ◽  
Coming Out ◽  
Single Mode ◽  
Femtosecond Laser Irradiation ◽  
Bragg Grating ◽  
Wavelength Shift ◽  
Radiation Resistant ◽  
Fbg Sensors

This paper demonstrates the fabrication of radiation-resistant fiber Bragg grating (FBG) sensors using infrared femtosecond laser irradiation. FBG sensors were written inside acrylate-coated fluorine-doped single-mode specialty optical fibers. We detected the Bragg resonance at 1542 nm. By controlling the irradiation conditions, we improved the signal strength coming out from the FBG sensors. A significant reduction in the Bragg wavelength shift was detected in the fabricated FBG sensors for a radiation dose up to 105 gray, indicating excellent radiation resistance capabilities. We also characterized the temperature sensitivity of the radiation-resistant FBG sensors and detected outstanding performance.

scholarly journals Tilted Fiber Bragg Grating Sensor Using Chemical Plating of a Palladium Membrane for the Detection of Hydrogen Leakage

Sensors ◽  
2018 ◽  
Vol 18 (12) ◽  
pp. 4478 ◽  
Author(s):  
Jiachen Yu ◽  
Zhenlin Wu ◽  
Xin Yang ◽  
Xiuyou Han ◽  
Mingshan Zhao
Keyword(s):  
Fiber Bragg Grating ◽  
Low Cost ◽  
Hydrogen Sensor ◽  
Bragg Grating ◽  
Wavelength Shift ◽  
Cross Sensitivity ◽  
Chemical Plating ◽  
Palladium Membrane ◽  
Surrounding Refractive Index ◽  
The Cross

A tilted fiber Bragg grating (TFBG) hydrogen sensor coated with a palladium (Pd) membrane by the electroless plating method is proposed in this paper. A uniform layer of Pd metal is fabricated in aqueous solutions by the chemical coating method, which is used as the sensitive element to detect the change of the surrounding refractive index (SRI) caused by hydrogen absorption. The change in SRI causes an unsynchronized change of the cladding modes and the Bragg peak in the TFBG transmission spectrum, thereby eliminating the cross-sensitivity due to membrane expansion and is able to simultaneously monitor the presence of cracks in the pipe, as well as the hydrogen leakage. By subtracting the wavelength shift caused by fiber expansion, the change of SRI, i.e., the information from the H2 level, can be separately obtained. The drifted wavelength is measured for the H2 concentration below the hydrogen explosion limit between 1% and 4%. The chemical-based coating has the advantages of a low cost, a simple operation, and being suitable for coating on long fiber structures. The proposed sensor is able to detect the H2 signal in 5 min at a 1% H2 concentration. The proposed sensor is proved to be able to monitor the hydrogen level without the cross-sensitivity of temperature variation and expansion strains, so could be a good candidate for security applications in industry.

scholarly journals Wavelength Shift Measurement Method Without Use of Spectrometer: The New Way for Environment Photonic Sensors

2018 ◽  
Vol 28 (2) ◽  
pp. 139
Author(s):  
Pham Van Hoi ◽  
Nguyen Thuy Van ◽  
Pham Van Dai ◽  
Le Huu Thang ◽  
Nguyen Van An ◽  
...  
Keyword(s):  
Fiber Bragg Grating ◽  
Low Cost ◽  
Bragg Grating ◽  
Wavelength Shift ◽  
Shift Measurement ◽  
Liquid Environment ◽  
Mixing Ratios ◽  
Narrow Line Width ◽  
Photonic Sensors ◽  
Testing Environments

The photonic sensors have shown very effectively for measuring the toxic contents in the liquid and air environments. In principle, the photonic sensors based on measurement of wavelength shift between reference condition and testing environments that we need use the spectrometer with high cost. In this paper, we present new configurations of photonic devices for measuring wavelength shift without use of spectrometer, which has a large potential for application in sensing technique with low cost. There are two configurations of photonic sensors are presented: i) first of them is based on fiber Bragg grating (FBG) combined with DFB laser diode with controlling wavelength emission by laser temperature and ii) second one is used  the fiber ring laser from Erbium-doped fiber and two FBG operated as  reference and sensing probe. The etched-fiber Bragg grating (e-FBG) as sensing probe is suitable for bio- and/ or chemical sensors. A novel photonic sensor can increase sensitivity and measuring accuracy of device by the narrow line-width of reflection spectra from laser and the sensor can determine a refractive index variation of 2x10-4, which is similarly for high resolution spectrometer. The experimental results show that this sensing method could determine different mixing ratios of organic solvents in liquid environment with good repeatability, high accuracy and rapid response.Keywords:

scholarly journals Simultaneous Measurement of Temperature and Mechanical Strain Using a Fiber Bragg Grating Sensor

Sensors ◽  
2020 ◽  
Vol 20 (15) ◽  
pp. 4223
Author(s):  
Shiuh-Chuan Her ◽  
Wei-Nan Lin
Keyword(s):  
Theoretical Prediction ◽  
Fiber Bragg Grating ◽  
Mechanical Strain ◽  
Bragg Grating ◽  
Wavelength Shift ◽  
Physical Parameters ◽  
Bragg Wavelength ◽  
Fbg Sensor ◽  
Host Structure ◽  
As Stress

Based on the shift of the Bragg wavelength, fiber Bragg grating (FBG) sensors have been employed to measure a variety of physical parameters such as stress, strain, displacement, temperature, vibration and pressure. In this work, a simple and easy way to be implemented FBG sensing methodology was proposed to measure the temperature and strain simultaneously. Half of the FBG was bonded on the host structure, while the other half of the FBG was left free. The host structure was an aluminum test specimen with dimensions of 20 × 3.8 × 0.5 cm3. As the host structure subjected to mechanical and thermal loadings, the Bragg wavelengths reflected from the bonded and unbonded FBGs are different. Theoretical predictions of the Bragg wavelength shifts of the bonded and unbonded FBGs were presented. Utilizing the Bragg wavelength shift of unbonded FBG, the temperature can be determined and is independent of mechanical strain. The Bragg wavelength shift of the bonded FBG allows the determination of the mechanical strain. The temperature measured by FBG sensor was compared with the result from a thermocouple, while the mechanical strain was validated with the theoretical prediction. Good agreement between the experimental measurement and theoretical prediction demonstrates that temperature-strain discrimination can be realized using the proposed method with one single FBG sensor.

scholarly journals Wireless, Portable Fiber Bragg Grating Interrogation System Employing Optical Edge Filter

Sensors ◽  
2019 ◽  
Vol 19 (14) ◽  
pp. 3222 ◽  
Author(s):  
Ken Ogawa ◽  
Shouhei Koyama ◽  
Yuuki Haseda ◽  
Keiichi Fujita ◽  
Hiroaki Ishizawa ◽  
...  
Keyword(s):  
Fiber Bragg Grating ◽  
Broad Band ◽  
Optical Power ◽  
Bragg Grating ◽  
Wavelength Shift ◽  
Laptop Computer ◽  
Bragg Wavelength ◽  
Amplifier Circuit ◽  
Edge Filter ◽  
Vital Sign Measurement

A small-size, high-precision fiber Bragg grating interrogator was developed for continuous plethysmograph monitoring. The interrogator employs optical edge filters, which were integrated with a broad-band light source and photodetector to demodulate the Bragg wavelength shift. An amplifier circuit was designed to effectively amplify the plethysmograph signal, obtained as a small vibration of optical power on the large offset. The standard deviation of the measured Bragg wavelength was about 0.1 pm. The developed edge filter module and amplifier circuit were encased with a single-board computer and communicated with a laptop computer via Wi-Fi. As a result, the plethysmograph was clearly obtained remotely, indicating the possibility of continuous vital sign measurement.

Determination of thermo-optic coefficient in liquids with fiber Bragg grating refractometer

2008 ◽  
Vol 281 (4) ◽  
pp. 621-625 ◽  
Author(s):  
R.C. Kamikawachi ◽  
I. Abe ◽  
A.S. Paterno ◽  
H.J. Kalinowski ◽  
M. Muller ◽  
...  
Keyword(s):  
Fiber Bragg Grating ◽  
Bragg Grating

Development of Fiber Bragg Grating (FBG) as Temperature Sensor Inside Packed-bed Non-thermal Plasma Reactor

2014 ◽  
Vol 68 (3) ◽  
Author(s):  
Siti Musliha Aishah Musa ◽  
RK Raja Ibrahim ◽  
Asrul Izam Azmi
Keyword(s):  
Fiber Bragg Grating ◽  
Temperature Variation ◽  
Thermal Plasma ◽  
Temperature Sensor ◽  
Plasma Reactor ◽  
Packed Bed ◽  
Bragg Grating ◽  
Wavelength Shift ◽  
Bragg Wavelength ◽  
Non Thermal Plasma

This paper presents early work on Fiber Bragg grating (FBG) as temperature sensor to monitor temperature variation inside a packed-bed non-thermal plasma reactor. FBG made from germania-doped fiber with center Bragg wavelength of 1552.5 nm was embedded inside non-thermal plasma reactor with sphere shape dielectric bead (barium titanate) and used to probe the temperature variation inside the reactor. The experimental works have proven that FBG is a suitable sensor to monitor temperature variation inside of reactor via LabVIEW program. Besides that, Optical Spectrum Analyzer (OSA) recorded Bragg wavelength shift as voltage of power supply increases, which indicate the non-uniform temperature variation occurring inside the reactor. However, it does not affect the chemical reaction inside the reactor because the temperature condition is in steady state.

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