440-4215/02 – Optical Communications III (OK III)
| Gurantor department | Department of Telecommunications | Credits | 6 |
| Subject guarantor | Ing. Jan Látal, Ph.D. | Subject version guarantor | prof. RNDr. Vladimír Vašinek, CSc. |
| Study level | undergraduate or graduate | Requirement | Choice-compulsory |
| Year | 2 | Semester | winter |
| | Study language | English |
| Year of introduction | 2015/2016 | Year of cancellation | 2023/2024 |
| Intended for the faculties | FEI | Intended for study types | Follow-up Master |
Subject aims expressed by acquired skills and competences
Understand the function of optical transmission routes.
Learning outcomes are set so that the students are able to identify and apply tasks in the field of optoelectronics.
Teaching methods
Lectures
Tutorials
Experimental work in labs
Summary
The subject gives an attention to optical detectors, optical amplifiers, how to project fiber optical communication systems, it describes coherent communication systems, WDM systems and soliton transmissions
Compulsory literature:
Recommended literature:
Filka,M.: Optoelectronics for telecommunications and informatics. ProfiberNetworking CZ,s.r.o., ISBN 987-80-86785-14-1
Additional study materials
Way of continuous check of knowledge in the course of semester
Conditions for credit granting:
Successfully passing of the two tests in exercises.
Handover of all protocols from laboratory measurements.
E-learning
Other requirements
The condition for the credit obtaining are handover of all reports from laboratory measurements and simulations and succesfully managing of two tests.
Prerequisities
Subject has no prerequisities.
Co-requisities
Subject has no co-requisities.
Subject syllabus:
Lectures:
Sources for optical communications-advanced description 1 -
Intrinsic semiconductors:Fermi enrgy levels and number of charge carriers, charge carriers density, effective mass of electrons and holes, doped semiconductors, materials for optical communications, PN junction unbiased, density of electrons and holes, biased PN junction, direct and indirect transitions, conservation of energy and momentum law, E-k diagram, Einstein´s rate relations, two-levels systems, equilibrium radiation from two-levels system, relationship between spontaneous and stimulated radiation, emission and absorption of radiation, absorption coefficient and linear coefficient of material amplification
Sources for optical communications-advanced description 2 -
Conditions for light amplification, population inversion-description, population inversion and methods of its realisation, three levels and four levels systems, optical feedback, phenomena in optical resonator, threshold condition for laser amplification, losses in optical resonator, total amplification and population inversion, amplification coefficient for small signals
Sources for optical communications-advanced description 3 -
Efficiency of laser diodes-internal, external, differential, power, laser resonator efficiency, threshold amplification and linewidth, radiating and nonradiating recombinations and their influence to laser diodes efficiency, conditions for high laser efficiency, heterosctuctures and their function, efficiency in terms of an E-k diagram, characteristics of laser diodes, threshold current and operating current of laser diode, spectral properties of LDs, radiation patterns of LD, longitudinal and transverse modes of laser radiation, LD modulation
Sources for optical communications-advanced description - 4
Theoretical limit of laser modulation rate, analog and digital modulation of LDs, rate equations of LD, relaxation oscillation of LD, Transfer function of LD, intensity modulation of LD, chirp, noise of LD, RIN and its description, transmitter modules, function block diagram, driving circuits of LD transmitters, link codes for data transmission, circuit solution of optical transmitters with LEDs and LDs
Sources for optical communications-advanced description - 5
Modulation circuits, controlling and monitoring circuits, coupling light from LED transmitter, coupling light from laser transmitter, backreflection protection of LD, integral characteristic of optical transmitter-eye diagram, faults of optical transmitters and their consequences in eye-diagram, internal and external modulators, Mach-Zehnder modulator, elektroabsorption modulator
Detectors and receivers for optical communications - advanced description 1
SNR a error rate of receiver, photodiode noise sources, shot noise, thermal noise, dark current, noise 1/f, noise equivalent circuit, total noise figure, normalised noise value, SNR for PIN photodiode, SNR for APD, dependence of SNR on APD amplification, noise equivalent power(NEP), bit error rate (BER), BER and decision threshold, error function(erf), complementary error function (erfc)
Detectors and receivers for optical communications - advanced description 2 -
BER description - Q parameter, relatioship between BER and SNR, BER versus Q parameter, minimum optical power - photodiode sensitivity, minimum number of photons per bit, quantum limit
Receiver units for opticalcommunications
Functional block diagram of optical receiver, input receiver unit, equivalent circuits of an optical front end, quantizer, clock recovery, decision circuit design, datasheets and parameters of optical receivers
Components of fiber optic networks 1
Point to point links, fiber optical networks, TDM and WDM, addúdrop problems, repeters and amplifiers in optical networks and signal amplifiers, passive and active elements of fiber optical networks, transceivers for fiber optic networks, transmitter requirements in WDM networks, tunable lasers, receivers for optical networks, receiver requirements in WDM networks, amplifiers in optical networks, functional types of optical amplifiers, semiconductor optical amplifiers(SOA), SOA advantages and disadvantages
Components of fiber optic networks 2
Fabry-Perot amplifier(FPA), travelling-wave amplifier(TWA), Gainf of FPA, gain of TWA, gain saturation, FPA bandwidth, TWA bandwidth, crosstalk, polarozation dependent gain, noise in optical amplifiers, amplified spontaneous emission ASE, datasheets and parameters of optical amplifiers
Components of fiber optic networks 3
Erbium doped fiber amplifiers (EDFA), principle of operation, energy band structure, amplifier pumping, C-band and L-band, gain and noise in EDFAs, EDFA components, splicing of erbium-doped fibers, ways to reduce splicing loss, pump laser diodes, datasheets and parameters of EDFAs, other types of optical networks amplifiers
Passive components of fiber optic networks 1
Fused biconical tapers and couplers, port configurations of couplers, characteristics of a WDM coupler, datasheets parameters of couplers, basics of WDM coupler theory, coupling length, phase mismatch, WDM multiplexers and demultiplexers, broadband narrowband WDM MUX/DEMUX
Passive components of fiber optic networks 2
Mux/Dmux, WDM waveguide gratings, WDM diffrection gratings, Fiber Bragg grating (FBG), WDM MUX/DEMUX applications, Add/Drop MUX/DEMUX and routers, optical filters, thin-film filters, tunable filters, acoustooptical filters, optical isolators, optical circulator, attenuators, variable attenuator, datasheet parameters, optical switches and functional modules, wavelength converters
Fiber optic systems and networks 1
Analog systems, direct intensity modulation, system planning, subcarrier intensity modulation, intensity modulation with two sidebands, frequency modulation, phase modulation, PAM, multiplex strategy
Fiber optic systems and networks 2
Coherent and phase modulated systems, principles of coherent detection, modulation formats, demodulation principles, differential phase modulation, ASK, FSK, PSK heterodyne detection, ASK and PSK homodyne detection, interferometric direct detection DPSK, systems with multiple carriers, polarisation multiplex
Exercises:
Calculation of the sensitivity of photodiodes, quiz
Calculation of SNR and BER
Laboratories:
Measurement of VA characteristics of LD and LED destination and bandwidth banned energy
Measurement P / I characteristics of LED and LD and the temperature dependence
Measurement of polarisation state and the LED lights LD
The measurement of light distribution in space and the impact of obstacles to the distribution
Measurement: SM fibre OTDR metro
Measurement ratio of decay and insertion of optical attenuation thread detention of members
Measurement of insertion of optical attenuation thread isolator
Measurement of optical amplifiers thread
Studying the properties of EDFA
Temperature Mach-thread-optical interferometer Mach-Zehnders interferomotters
Measurement of the spectral characteristics of LED and LD for different currents
Measurement shift maximum wavelength LD with the current budicím-
Conditions for subject completion
Occurrence in study plans
Occurrence in special blocks
Assessment of instruction
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