A Prototype of Fiber Bragg Grating Dendrometric Sensor for Monitoring the Growth of the Diameter of Trees in the Amazon

In this work, we propose a fiber optic point dendrometer with two Fiber Bragg Grating (FBG) sensors capable of simultaneously measuring strain and temperature considered suitable for monitoring the growth of the diameter of trees in the Amazon compared to conventional electrical sensors and we perform a simulation on the performance of the sensors for measuring the diameter using the Coupled Mode Theory (CMT) and the Transfer Matrix Method (TMM). A measure of the diameter variation was suggested and the sensitivity of the sensors were analyzed from the measurements of the displacements of the Bragg wavelengths varying simultaneously the strain and the temperature. The results showed that the proposed configuration, thermally varied from 0 °C to 80 °C and deformed from 0 to 2400 μ could specifically detect minute variations in diameters with a resolution of 0.5 μm (0.0005 mm) with good linearity staying with a variation of the Bragg wavelength 0.12 nm for each 10 °C and 0.24 nm for each 200 μ. The feasibility of using this type of configuration of FBG sensors for strain and temperature measurements in the monitoring of forest, forestry, climate change and irrigation areas in the Amazon is very promising.

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Comparison of Fabry – Perot Filter of Fiber Bragg Grating for Visible and Ultraviolet Spectra

KnE Engineering ◽

10.18502/keg.v0i0.517 ◽

2016 ◽

Vol 1 (1) ◽

Author(s):

Didik Puji Sutriyono

Keyword(s):

Visible Light ◽

Fiber Bragg Grating ◽

Transfer Matrix Method ◽

Matrix Method ◽

Laser Source ◽

Bragg Grating ◽

Coupled Mode Theory ◽

Coupled Mode ◽

Ultraviolet Spectra ◽

Fabry Perot

<p>The use of Fiber Bragg Grating (FBG) as Fabry – Perot filter has been successfully developed for visible light and ultraviolet spectra. The characteristic of FBG is analyzed by using computational model with Transfer Matrix Method by order 2 with the coupled mode theory. The reflectivity, length of grating and bandwidth are parameters to determine the performance of FGB with laser source of 1 mW for 250 – 350 nm, ultraviolet and 380 – 780 nm, visible light. The simulation is also carried out by various grating from 0.5 cm – 9.5 cm with increment step of 1 cm. The simulation result showed that there is the filter discrepancy for maximum peak. This design of FGB can be used as a filter. Only selected wavelength is allowed to transmit the signal until the end of the optical fiber.</p>

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Comparison of Fabry – Perot Filter of Fiber Bragg Grating for Visible and Ultraviolet Spectra

KnE Engineering ◽

10.18502/keg.v1i1.517 ◽

2016 ◽

Vol 1 ◽

Author(s):

Didik Puji Sutriyono

Keyword(s):

Visible Light ◽

Fiber Bragg Grating ◽

Transfer Matrix Method ◽

Matrix Method ◽

Laser Source ◽

Bragg Grating ◽

Coupled Mode Theory ◽

Coupled Mode ◽

Ultraviolet Spectra ◽

Fabry Perot

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Phase-modified coupled mode theory for calculation of fiber Bragg grating Fabry-Perot cavity transmission spectrum

Acta Physica Sinica ◽

10.7498/aps.57.6393 ◽

2008 ◽

Vol 57 (10) ◽

pp. 6393

Author(s):

Wang Yan-Hua ◽

Ren Wen-Hua ◽

Liu Yan ◽

Tan Zhong-Wei ◽

Jian Shui-Sheng

Keyword(s):

Fiber Bragg Grating ◽

Transmission Spectrum ◽

Bragg Grating ◽

Coupled Mode Theory ◽

Mode Theory ◽

Coupled Mode ◽

Cavity Transmission ◽

Fabry Perot

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Numerical and Experimental Performance Analysis of the Chirped Fiber Bragg Grating Based Abrasion Sensor for the Maintenance Applications in the Industry 4.0

Sensors ◽

10.3390/s20030770 ◽

2020 ◽

Vol 20 (3) ◽

pp. 770

Author(s):

Konrad Markowski ◽

Kacper Wojakowski ◽

Ernest Pokropek ◽

Michał Marzęcki

Keyword(s):

Fiber Bragg Grating ◽

Fiber Optics ◽

Cost Effective ◽

Bragg Grating ◽

Coupled Mode Theory ◽

Spectral Position ◽

Experimental Performance ◽

Coupled Mode ◽

Extensive Analysis ◽

Chirped Fiber Bragg Grating

In this article, an extensive analysis of the performance of the fiber optics-based abrasion sensor that utilizes chirped fiber Bragg grating, is presented. For the response investigation during abrasion, a numerical analysis, based on the transfer matrix method and coupled mode theory, is provided. The influence of the SLED source spectral position in respect to the spectral position of the chirped fiber Bragg grating is evaluated together with the influence of the changes of the ambient temperature of the sensor. Experimental verification of the sensor’s performance is provided, together with the proposition of the packaging of the sensor. In the article, a simple, cost-effective and multiplexation-ready concept of the wear or abrasion sensor system is presented and discussed.

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TEMPERATURE AND WATER LEVEL MEASUREMENT OF LIQUID IN A TANK USING FIBER BRAGG GRATING

Jurnal Teknologi ◽

10.11113/jt.v78.7529 ◽

2016 ◽

Vol 78 (3) ◽

Cited By ~ 3

Author(s):

Odai Falah Ameen ◽

Marwan Hafeedh Younus ◽

M. S. Aziz ◽

RK Raja Ibrahim

Keyword(s):

Water Level ◽

Fiber Bragg Grating ◽

Linear Response ◽

Liquid Level ◽

Laser Source ◽

Bragg Grating ◽

Bragg Wavelength ◽

Work Measurement ◽

Level Measurement ◽

Fbg Sensors

In this work, measurement of temperature and liquid level were performed simultaneously using fiber Bragg grating (FBG) sensors. A multi-channel Fibre Interrogator with built-in ASE laser source operating around 1552 to 1568 nm was employed to record a shift in Bragg wavelength due to contribution from both temperature and hydrostatic pressure of liquid weight in the tank. Results show a linear response between liquid level and temperature readings against the shift in Bragg wavelength for liquid level up to 85 cm in height and the temperature range of 27 to 77 oC. The sensitivity of the sensor head for water level measurement is 10.57 pmcm-1, while the sensitivity for temperature measurement is 11.28 pm/oC respectively.

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Coupled-mode theory for magneto-optical fiber Bragg grating under non-uniform magnetic field

Optoelectronics Letters ◽

10.1007/s11801-011-0095-y ◽

2011 ◽

Vol 7 (5) ◽

pp. 354-357 ◽

Cited By ~ 1

Author(s):

Fen Liu ◽

Bao-jian Wu ◽

Xin Lu

Keyword(s):

Magnetic Field ◽

Optical Fiber ◽

Fiber Bragg Grating ◽

Uniform Magnetic Field ◽

Bragg Grating ◽

Coupled Mode Theory ◽

Mode Theory ◽

Coupled Mode ◽

Optical Fiber Bragg Grating

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Design Reliable Bus Structure Distributed Fiber Bragg Grating Sensor Network Using Gated Recurrent Unit Network

Sensors ◽

10.3390/s20247355 ◽

2020 ◽

Vol 20 (24) ◽

pp. 7355

Author(s):

Amare Mulatie Dehnaw ◽

Yibeltal Chanie Manie ◽

Ya Yu Chen ◽

Po Han Chiu ◽

Hung Wei Huang ◽

...

Keyword(s):

Sensor Networks ◽

Fiber Bragg Grating ◽

Wavelength Division Multiplexing ◽

Bragg Grating ◽

Bragg Wavelength ◽

Wavelength Division ◽

Fbg Sensor ◽

Bus Structure ◽

Fbg Sensors ◽

Gated Recurrent Unit

The focus of this paper was designing and demonstrating bus structure FBG sensor networks using intensity wavelength division multiplexing (IWDM) techniques and a gated recurrent unit (GRU) algorithm to increase the capability of multiplexing and the ability to detect Bragg wavelengths with greater accuracy. Several Fiber Bragg grating (FBG) sensors are coupled with power ratios of 90:10 and 80:10, respectively in the suggested experimental setup. We used the latest IWDM multiplexing technique for the proposed scheme, as the IWDM system increases the number of sensors and allows us to alleviate the limited operational region drawback of conventional wavelength division multiplexing (WDM). However, IWDM has a crosstalk problem that causes high-sensor signal measurement errors. Thus, we proposed the GRU model to overcome this crosstalk or overlapping problem by converting the spectral detection problem into a regression problem and considered the sequence of spectral features as input. By feeding this sequential spectrum dataset into the GRU model, we trained the GRU system until we achieved optimal efficiency. Consequently, the well-trained GRU model quickly and accurately identifies the Bragg wavelength of each FBG from the overlapping spectra. The Bragg wavelength detection performance of our proposed GRU model is tested or validated using different numbers of FBG sensors, such as 3-FBG, 5-FBG, 7-FBG, and 10-FBG, separately. As a result, the experiment result proves that the well-trained GRU model accurately identifies each FBG Bragg wavelength, and even the number of FBG sensors increase, as well as the spectra of FBGs, which are partially or fully overlapped. Therefore, to boost the detection efficiency, reliability, and to increase the multiplexing capabilities of FBG sensor networks, the proposed sensor system is better than the other previously proposed methods.

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Enhancing Temperature Sensitivity Using Cyclic Polybutylene Terephthalate- (c-PBT-) Coated Fiber Bragg Grating

Journal of Sensors ◽

10.1155/2018/3790326 ◽

2018 ◽

Vol 2018 ◽

pp. 1-6 ◽

Cited By ~ 3

Author(s):

H. Ahmad ◽

S. F. S. M. Noor ◽

A. F. Arusin ◽

S. A. Samsudin ◽

K. Thambiratnam ◽

...

Keyword(s):

Fiber Bragg Grating ◽

Temperature Sensitivity ◽

Real World ◽

Operating Temperature ◽

Bragg Grating ◽

Wavelength Shift ◽

Polybutylene Terephthalate ◽

Bragg Wavelength ◽

Real World Applications ◽

Fbg Sensors

A polybutylene terephthalate (c-PBT) coating for enhancing the temperature sensitivity of a fiber Bragg grating- (FBG-) based sensor is proposed and demonstrated. The coating is seen to increase the sensitivity of the proposed sensor by a factor of approximately 11 times as compared to a bare FBG, giving a Bragg wavelength shift of 0.11 nm/°C with an operating temperature ranging from 30°C to 87°C. The proposed sensor is also easy to fabricate as compared to other similarly coated FBG sensors, giving it a significant advantage for field applications with the added advantage of being easily reformed to fit various housings, making it highly desirable for multiple real-world applications.

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Analytical Model Analysis of Reflection/Transmission Characteristics of Long-Period Fiber Bragg Grating (LPFBG) by Using Coupled Mode Theory

Journal of Optical Communications ◽

10.1515/joc-2019-0187 ◽

2020 ◽

Vol 0 (0) ◽

Author(s):

Iraj Sadegh Amiri ◽

Ahmed Nabih Zaki Rashed ◽

P. Yupapin

Keyword(s):

Fiber Bragg Grating ◽

Transmission Coefficient ◽

Analytical Model ◽

Bragg Grating ◽

Coupled Mode Theory ◽

Transmission Characteristics ◽

Mode Theory ◽

Coupled Mode ◽

Long Period ◽

Operating Wavelength

AbstractThis study presents an analytical model analysis of reflection/transmission characteristics of long-period fiber Bragg grating (LPFBG) by using coupled mode theory. Reflected signal power is deeply studied against grating length at the optimum operating signal wavelength of 1550 nm for the proposed and previous models. Reflectivity and transmission coefficient are also clarified versus operating wavelength for the previous model and proposed a model with a central wavelength of 1550 nm, Δn = 0.003 and optimum grating length of 30 mm. In the same way, the reflectivity and transmission coefficient are outlined against relative refractive grating difference step at the optimum wavelength of 1550 nm and optimum grating length of 30 mm. The optimum LPFBG can be achieved with the optimum grating length of 30 mm, operating wavelength of 1550 nm and relative refractive grating difference step of 0.3 %.

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