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Effect of PWM control of a Laser Diode on Its Characteristics
Folta, Lukáš ; Ing. Jan Látal, Ph.D. (VŠB-TUO) (referee) ; Šťáva, Martin (advisor)
This bachelor's thesis deals with the measurement of the characteristics of two semiconductor laser diodes (LD) and its automation. The effect of current control method and LD temperature is compared here. The first chapter is devoted to the theoretical basis of the sub-areas of the experiments, a literature review dealing with laser control using pulse width modulation (PWM) is carried out, and the method of realization of the measured experiments is presented. The second chapter first defines the methods of recalculating the measured data and determines their uncertainties. The following are three subsections presenting the results of individual experiments. The first experiment deals with continuous control and the other two deal with pulse control, one using a commercially available laser driver and the other using a switch designed primarily for this work. The conclusion of the work contains a comparison of the measured results, evaluates their usability and suggests possible extensions of this work.
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OTDR optical path analyzer
Šimková, Barbora ; Tomašov, Adrián (referee) ; Dejdar, Petr (advisor)
The aim of this master's thesis was a theoretical analysis of OTDR issues, analysis of OTDR device components, as well as basic parameters of this device. The thesis also includes a theoretical analysis of reflections, scattering, and various types of connectors. In the practical part, a circuit design for OTDR measurement was developed and subsequently implemented. The circuit was realized using the Red Pitaya development board and Koheron laser. Additionally, a circuit for direct method measurement was also created. In the LabView development environment, a program was created, including a graphical user interface. A laboratory task was also designed to provide a basic understanding of OTDR measurement issues.
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Laboratory exercise - OTDR optical path analyzer
Šimková, Barbora ; Münster, Petr (referee) ; Dejdar, Petr (advisor)
The bachelor's thesis consists of detailed analysis of OTDR problematics and implementation of the connection. Part of the work also consists of theoretical analysis of optical fibers and their transmission properties, especially dispersion and diffraction. Realization of the connection was made using platform Red Pitaya and laserboard Koheron. Final program was created in development environment LabView. The program also contains graphical user interface.
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Measurement of basic parameters of optical and optoelectronic components
Beneš, Pavel ; Látal, Michal (referee) ; Münster, Petr (advisor)
This diploma thesis deals with optical and optoelecronic components. The first part of the work describes the optical paths and methods of their measurement. The second part describes the coupler, circulator and isolator. Further described is a laser diode, a photodetector and a modulator. The third part describes the measurement procedure of the coupler, circulator, isolator, laser diode, photodetector and modulator. The measured values are compared with the catalog values.
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Design and realization of photodetector using Arduino platform
Vrána, Milan ; Háze, Jiří (referee) ; Veverka, David (advisor)
Arduino, Arduino Nano, Processing, photodetector, optical gate, communication, UART, I2C, interrupt, timer, application, temp measurement, humidity measurement, electroscope, 3D print
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Fiber optical transmission system
Horský, Tomáš ; Münster, Petr (referee) ; Dejdar, Petr (advisor)
Bachelor thesis deals with the program processing for the simulation of dispersion on the optical transmission. Parameters of optical fiber, such as attenuation, diffusion, dispersion, and bandwidth are described in the theoretical part. The main focus is on dispersion while being the key parameter of this work. In the practical part, the measurement characteristics of the eye diagram and its analysis are discussed. Simulator of dispersion can serve both for simulation as well as a measuring device for real transmission routes.
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Optical Fiber Sensors
Krejsa, Jan ; Šedivá, Soňa (referee) ; Bejček, Ludvík (advisor)
The diploma thesis focuses on optical fiber sensors with detailed preview of the turbidity sensor, its design and testing. The introduction deals with the general theory of fiber sensors and measurement methodology of physical variables. This part is followed by a charter focusing on the possible ways of measuring turbidity. Furthermore, the diploma thesis introduces design of the new turbidity sensor which is realized with consideration of the industrial usage and future application to the automated process of beer production. It also includes a detailed description of the hardware and software sensors created within this thesis. The last section is devoted to a calibration and testing functionality of turbidity sensor.
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Photoreceivers with modern integrated circuits
Matyáš, Petr ; Murina, Milan (referee) ; Drexler, Petr (advisor)
The main goal of the bachelors project is to find the proper device to design a receiver of the anologue modulated optical signal. The only condition is to use the device, which is able to output the signal of 100 MHz bandwidth. The theoretical part concerned on description of main types of a photodiode and its basic features, its advantages and disadvantages. Different circuit applications of photodiode are presented. The main advantages of using operational amplifiers in those circuits are shown. In the next part of the project a few types of circuit connections of photodiode are presented. The circuit with transimpedance amplifier is chosen as the most suitable for the required application. The next step is to select the proper electronic device. According to technical catalogues classical operational amplifier TEXAS INSTRUMENT OPA657 was proposed. Nevertheless program simulation of the designed cicuit shows that required bandwidth cannot be reached with this device. At last transimpedance amplifier ANALOG DEVICES AD8015 comes into account as suitable solution. Final analysis and calculation determine the designed circuit with this device for range up to 240MHz of output signal.
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Optical beam intensity profile analysis
Fojtík, Jakub ; Vitásek,, Jan (referee) ; Barcík, Peter (advisor)
This work is focused on the study of the intensity profile of optical beams. In the first part problematics of optical beams from theoretical point of view is discussed, Model of realistically circular symmetric beam in an ideal lossless, stationary, homogeneous and isotropic medium is formed in Matlab®. The next part of the thesis deals with implementation of automatic workplace for measuring intensity profile of optical beams. Within the thesis - PCB desing of photodetector in Eagle®, is discussed. Custom application for controlling the motorized linear stage M – IMS 400 and communication with photodetector in the Microsoft Visual Studio 2010® was created.
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Digital data recorder
Müller, Tomáš ; Skapa,, Jan (referee) ; Diblík, Jan (advisor)
This thesis deals with method of measuring optical beam intensity, searching for communication system beam using stepper motor movement of the optical head and processing measured signal for displaying on PC. The basic theory of optoelectronics is shown here concerning the problem. There is elaborated main principles of photodetector and stepper motor mainly, which are main part of device. The second part of work is theoretical design of data recorder. All parts are described individually-their characteristics and conditions for correct usage. In the last part setup of device is explained, with the references to blocks of written programs. In the last part, main funcrions of system, its hardware managing and communication are described. At the very end of thesis, examples of measured data are presented.
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