Design and realization of FBG sensors for selected physical quantities measurement

Celá táto diplomová práca sa zaoberá optickými vláknami, v ktorých je vytvorená Braggova mriežka. Najskôr si v teoretickej časti priblížime čo to vôbec optické vláknové Braggové mriežky sú, aké metódy sa používajú pri výrobe, jednotlivé typy Braggových mriežok a na koniec ich príkladné využitie v praxi. V praktickej časti sa najskôr zaoberám samotným návrhom a realizáciou senzorov na meranie rôznych fyzikálnych veličín za pomoci optických Braggových mriežok. Následne už s vyrobenými senzormi testujem ich funkčnosť pomocou meraní a následne spracovávam namerané dáta. Keďže sa optické Braggove mriežky čoraz častejšie objavujú v rôznych senzoroch na meranie fyzikálnych veličín predpokladám, že mnou vyrobené senzory by mali byť plne funkčné. Ich citlivosť a rozsah budú ovplyvnené najmä materiálom, ktorý použijem na ich výrobu.This thesis deals with optical fibers in which Bragg grid is created. First of all, in the theoretical part, we will describe what optical fiber Bragg grids are, what methods are used in production, the different types of Bragg grids and, in the end, their practical application. In the practical part I first deal with the design and implementation of sensors for measuring various physical quantities using optical Bragg grids. Subsequently, with the sensors produced, I test their functionality using measurements and then process the measured data. As optical Bragg grids appear more and more often in various sensors for measuring physical quantities, I assume that sensors made by me should be fully functional. Their sensitivity and extent will be influenced mainly by the material I use for their production.440 - Katedra telekomunikační technikyvýborn

Determine the effect of thermal stress on the optical coupler

Import 23/08/2017Celá táto bakalárska práca sa zaoberá pasívnymi optickými rozbočovačmi, alebo aj couplermi, ktoré sú vystavené tepelnému namáhaniu. Cieľom práce je priblížiť si coupler a optické siete po teoretickej stránke a zistiť ako vplýva tepelné namáhanie na jednotlivé útlmové parametre couplerov. V prvej časti práce, ktorá je teoretická, sa zoznámime s jednotlivými parametrami a vlastnosťami optických sietí a couplerov, ktoré sú neoddeliteľnou súčasťou optických sietí. V praktickej časti sa už zaoberáme samotným pôsobením tepelného namáhania na parametre optických couplerov. Významnými parametrami merania sú celkové straty, vložné útlmy, homogenita strát, deliace pomery a smerovosti. Keďže sme umiestnili couplery pod stále tepelné namáhanie predpokladáme postupné zvyšovanie útlmu. Jedná sa však len o prvotný pohľad na túto problematiku.The whole bachelor thesis concerns with passive optical splitters or couplers which are exposed to thermal stress. The aims of this work are a theoretical description of the coupler and optical networks and finding the influence of thermal stress on the individual attenuation parameters of couplers. In the first part which is theoretical, we specify individual parameters and properties of optical networks and couplers which are an integral part of optical systems. The practical part is already engaged in the effect of thermal stress on parameters of optical couplers. Important parameters of measurements are total losses, insertion losses, homogeneity of the losses, split ratios and directionalities. We expect a gradual increase in attenuation while couplers are placed under thermal stress. However, this is only the initial view into this issue.440 - Katedra telekomunikační technikyvýborn

Portable optical fiber Bragg grating sensor for monitoring traffic density

The paper examines the development of a portable sensor strip with fiber optic Bragg grating for monitoring urban traffic density up to 80 kph. It contains a 2.5-m-long and a 2-cm-high sensor created from a combination of silicone addition rubber (bicomponent addition silicone rubber) and Bragg grating placed inside a carbon tube. The design of the portable sensor permits traffic density and cars crossings to be monitored and detected in a single lane. The functionality of the sensor was verified in real traffic; the results of this study are based on the detection of 1518 vehicles of different types and sizes. According to the measurements, the sensor is characterized by a high detection rate of 98.946%.Web of Science922art. no. 479

Pressure membrane FBG sensor realized by 3D technology

The publication describes the design, production, and practical verification of an alternative pressure sensor suitable for measuring the pressure of gas, based on a combination of fiber-optic technology and 3D printing methods. The created sensor uses FBG (Fiber Bragg Grating) suitably implemented on a movable membrane. The sensor is equipped with a reference FBG to compensate for the effect of ambient temperature on the pressure measurement. The sensor is characterized by its immunity to EM interference, electrical passivity at the measuring point, small size, and resistance to moisture and corrosion. The FBG pressure sensor has a pressure sensitivity of 9.086 pm/mbar in the range from 0 to 9 mbar with a correlation coefficient of 0.9982. The pressure measurement in the specified range shows an average measurement error of 0.049 mbar and a reproducibility parameter of 0.0269 +/- 0.0135 mbar.Web of Science2115art. no. 515

PDMS-FBG-based fiber optic system for traffic monitoring in urban areas

This article introduces fiber Bragg grating (FBG) system for monitoring selected traffic flow parameters in urban areas. The system is able to monitor traffic density or speed of cars driving in single lane. The proposed system consists of five Bragg gratings encapsulated in Polydimethylsiloxane polymer and is characterized by easy and inexpensive installation in the milled upper layer of the road covered with an asphalt mixture. The results of first operational tests presented in this study include 3978 passing vehicles of various specifications. The system's vehicle detection success rate is 99.62%. And further, a mean absolute error 1.35 kph and a relative error 2.62% when measuring vehicle speed.Web of Science812765812764