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Laser diodes controller utilizing AVR microcontroller
Boštík, Jiří ; Šilhavý, Pavel (referee) ; Krajsa, Ondřej (advisor)
This thesis deals with the design and subsequent realization of laser diode control devices. The circuit will be able to control the diode with using a laser driver, via a computer network or via the display for control current values, setting of initial values and more. The device will be connected also with a SD card for saving of settings. In the theoretical part there are described individual components that are needed for functionality of the device. The practical part contains a block diagram, in which is described complete feature of the device, then a draft scheme with a description of all integrated circuits and important components. At the end of this work is described the software that controls the entire designed device.
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Laser Diode Controller with Analog Modulation
Král, Vojtěch ; Dobesch, Aleš (referee) ; Barcík, Peter (advisor)
The Bachelor thesis deals with a design of the controller for a laser diode with the possibility of analog modulation. The basic parameters (current, voltage, temperature and optical power) are shown on an alphanumeric LCD display with the driver SPLC780. Core of this project is the laser driver MLD203CHB. Control is realized by buttons, which are setting the value of digital potenciometre, which is connected to the reference. Everything is controlled by the microcontroller ATMGEA328P. Temperature is measured with the analog sensor TMP36. Cooling of the laser diode is implemented by a peltier module controlled by the microcontroller.
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Wireless optical links in LAN and MAN networks
Šporik, Jan ; Dostál, Otto (referee) ; Filka, Miloslav (advisor)
The main aim of this thesis is the design of an optical wireless link that is transmitted in free space, in the atmosphere. The thesis describes the composition of heads of the atmospheric optical link. One part of this work focuses on the issue of the spread of optical beam in the atmosphere. The facts which have a major impact on the transmission of optical radiation in free space are pointed out here as well. In this work phenomena of absorption, refraction of light, turbulence and dispersion are discussed. Wavelengths spread in the atmosphere with different decline and therefore this thesis provides an analysis of the use of wavelengths between 750 and 1600 nm depending on the meteorological visibility. It describes the basis of the design of AOS through stationary model using power balance equation. It depicts the description of the statistical model, which makes possible to determine the availability on the basis of probability. Current possibilities of AOS are in general described in this work. The practical part of the work is focused on the design of simulation model of transmitter and receiver AOS in the program Pspice. The receiver and transmitter are designed to replace transiver in the media converter. The receiver plays a key role, and therefore big part of the thesis is given to it. Receiver model is composed of a photodiode and of an transimpedance amplifier. The receiver circuit has been tested. The model of transmitter shows the principle of modulating of current, which flows in laser diode. This work does not carried the model of atmosphere, which would serve as a link between the receiver and the transmitter. The circuit of the receiver is subjected to the noise analysis. Parameter NEP and SNR is designed. Link budget is calculated for models of the receivers and the transmitters. The maximum distance of heads is set based on the requirements for a BER error rate which combine this condition. The design of the practical implementation results from the models of transmitters and receivers. Printed circuit boards are designed in EAGLE. Within the frame of this thesis no curcuit diagram is carried out.
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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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Laser Diode Controller with Analog Modulation
Král, Vojtěch ; Dobesch, Aleš (referee) ; Barcík, Peter (advisor)
The Bachelor thesis deals with a design of the controller for a laser diode with the possibility of analog modulation. The basic parameters (current, voltage, temperature and optical power) are shown on an alphanumeric LCD display with the driver SPLC780. Core of this project is the laser driver MLD203CHB. Control is realized by buttons, which are setting the value of digital potenciometre, which is connected to the reference. Everything is controlled by the microcontroller ATMGEA328P. Temperature is measured with the analog sensor TMP36. Cooling of the laser diode is implemented by a peltier module controlled by the microcontroller.
|
|
|
Laser diodes controller utilizing AVR microcontroller
Boštík, Jiří ; Šilhavý, Pavel (referee) ; Krajsa, Ondřej (advisor)
This thesis deals with the design and subsequent realization of laser diode control devices. The circuit will be able to control the diode with using a laser driver, via a computer network or via the display for control current values, setting of initial values and more. The device will be connected also with a SD card for saving of settings. In the theoretical part there are described individual components that are needed for functionality of the device. The practical part contains a block diagram, in which is described complete feature of the device, then a draft scheme with a description of all integrated circuits and important components. At the end of this work is described the software that controls the entire designed device.
|
|
|
Wireless optical links in LAN and MAN networks
Šporik, Jan ; Dostál, Otto (referee) ; Filka, Miloslav (advisor)
The main aim of this thesis is the design of an optical wireless link that is transmitted in free space, in the atmosphere. The thesis describes the composition of heads of the atmospheric optical link. One part of this work focuses on the issue of the spread of optical beam in the atmosphere. The facts which have a major impact on the transmission of optical radiation in free space are pointed out here as well. In this work phenomena of absorption, refraction of light, turbulence and dispersion are discussed. Wavelengths spread in the atmosphere with different decline and therefore this thesis provides an analysis of the use of wavelengths between 750 and 1600 nm depending on the meteorological visibility. It describes the basis of the design of AOS through stationary model using power balance equation. It depicts the description of the statistical model, which makes possible to determine the availability on the basis of probability. Current possibilities of AOS are in general described in this work. The practical part of the work is focused on the design of simulation model of transmitter and receiver AOS in the program Pspice. The receiver and transmitter are designed to replace transiver in the media converter. The receiver plays a key role, and therefore big part of the thesis is given to it. Receiver model is composed of a photodiode and of an transimpedance amplifier. The receiver circuit has been tested. The model of transmitter shows the principle of modulating of current, which flows in laser diode. This work does not carried the model of atmosphere, which would serve as a link between the receiver and the transmitter. The circuit of the receiver is subjected to the noise analysis. Parameter NEP and SNR is designed. Link budget is calculated for models of the receivers and the transmitters. The maximum distance of heads is set based on the requirements for a BER error rate which combine this condition. The design of the practical implementation results from the models of transmitters and receivers. Printed circuit boards are designed in EAGLE. Within the frame of this thesis no curcuit diagram is carried out.
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