|
|
Wideband transimpedance photodiode amplifier
Šťastný, Martin ; Roubal, Zdeněk (referee) ; Drexler, Petr (advisor)
This thesis deals with the design of transimpedance amplifier with high gain. There are described different principles of semiconductor sensors of optical signal. There is also a comparison of different methods of converting the photocurrent to voltage. It also discusses the design of an appropriate feedback capacitor in terms of stability in participation as a transimpedance amplifier. It examines the impact of non-zero currents flowing to the input operational amplifier circuit functionality and output offset compensation. Part of the thesis is a simulation that confirms the calculated values. The thesis also deals with the implementation of the receiver and the method of correct measurement of the cut-off frequency.
|
|
|
Amplifier for semiconductor photomultiplier
Vomela, Roman ; Barcík, Peter (referee) ; Kolka, Zdeněk (advisor)
This bachelor thesis deals with design of an amplifier for semiconductor photomultiplier. A semiconductor photomultiplier combines tens to hundreds of avalanche photodiodes into a matrix capable of detecting incident photons. The output of the photomultiplier are pulses with an amplitude of about 1 mV whose mean frequency corresponds to the incidence optical power. Based on the analysis of the experimentally obtained output signal, three solutions were proposed: an amplifier with operational amplifiers, a variable gain amplifier and a monolithic amplifier circuit. These three solutions were compared in terms of bandwidth, noise and power consumption, and a variant with operational amplifiers was chosen for implementation. To verify the properties of the amplifier, an auxiliary printed circuit board with a power supply circuit was implemented.
|
|
|
Long Range Free Space Optical Links
Křivák, Petr ; Vlček, Čestmír (referee) ; Vašinek, Vladimír (referee) ; Wilfert, Otakar (advisor)
This dissertation thesis deals with a long range free space optical links for communication over the distance of few tens of kilometers in the atmosphere. The problematic of the beam propagation and atmospheric effects influencing the beam and the quality of the communication protocol are discussed. The measuring link is also designed to study the parameters of the communication link work conditions. The measuring link consists of two heads. The transmitter head is designed to use two optical beams with laser diodes at the wavelength of the atmospheric windows 850 or 1550 nm and the overall power of hundredths of mW. The receiver head includes the Fressnel lens. For the detection of very weak signal, the avalanche photodiode is used. In the end of this work, due to the high power of the transmitting optical beam, the laser safety conditions are also discussed, including the deduced optical transmitters construction recommendations.
|
|
|
Interface for optical pulse detector
Dušek, Filip ; Barcík, Peter (referee) ; Kolka, Zdeněk (advisor)
This bachelor thesis deals with the design, realization, and testing of the interface for the optical pulses detector. The interface consists of 3 parts – the photodetector, the preamplifier, the adjustable source. Supply source for avalanche photodiode includes experimental function for voltage automatic setting with the help of gain measurement. Photodetector is complemented by a wideband amplifier with gain 19dB.
|
|
|
Interface for optical pulse detector
Dušek, Filip ; Barcík, Peter (referee) ; Kolka, Zdeněk (advisor)
This bachelor thesis deals with the design, realization, and testing of the interface for the optical pulses detector. The interface consists of 3 parts – the photodetector, the preamplifier, the adjustable source. Supply source for avalanche photodiode includes experimental function for voltage automatic setting with the help of gain measurement. Photodetector is complemented by a wideband amplifier with gain 19dB.
|
|
|
Amplifier for semiconductor photomultiplier
Vomela, Roman ; Barcík, Peter (referee) ; Kolka, Zdeněk (advisor)
This bachelor thesis deals with design of an amplifier for semiconductor photomultiplier. A semiconductor photomultiplier combines tens to hundreds of avalanche photodiodes into a matrix capable of detecting incident photons. The output of the photomultiplier are pulses with an amplitude of about 1 mV whose mean frequency corresponds to the incidence optical power. Based on the analysis of the experimentally obtained output signal, three solutions were proposed: an amplifier with operational amplifiers, a variable gain amplifier and a monolithic amplifier circuit. These three solutions were compared in terms of bandwidth, noise and power consumption, and a variant with operational amplifiers was chosen for implementation. To verify the properties of the amplifier, an auxiliary printed circuit board with a power supply circuit was implemented.
|
|
|
Wideband transimpedance photodiode amplifier
Šťastný, Martin ; Roubal, Zdeněk (referee) ; Drexler, Petr (advisor)
This thesis deals with the design of transimpedance amplifier with high gain. There are described different principles of semiconductor sensors of optical signal. There is also a comparison of different methods of converting the photocurrent to voltage. It also discusses the design of an appropriate feedback capacitor in terms of stability in participation as a transimpedance amplifier. It examines the impact of non-zero currents flowing to the input operational amplifier circuit functionality and output offset compensation. Part of the thesis is a simulation that confirms the calculated values. The thesis also deals with the implementation of the receiver and the method of correct measurement of the cut-off frequency.
|
|
|
Long Range Free Space Optical Links
Křivák, Petr ; Vlček, Čestmír (referee) ; Vašinek, Vladimír (referee) ; Wilfert, Otakar (advisor)
This dissertation thesis deals with a long range free space optical links for communication over the distance of few tens of kilometers in the atmosphere. The problematic of the beam propagation and atmospheric effects influencing the beam and the quality of the communication protocol are discussed. The measuring link is also designed to study the parameters of the communication link work conditions. The measuring link consists of two heads. The transmitter head is designed to use two optical beams with laser diodes at the wavelength of the atmospheric windows 850 or 1550 nm and the overall power of hundredths of mW. The receiver head includes the Fressnel lens. For the detection of very weak signal, the avalanche photodiode is used. In the end of this work, due to the high power of the transmitting optical beam, the laser safety conditions are also discussed, including the deduced optical transmitters construction recommendations.
|
guest ::
