440-4215/03 – Optical Communications III (OK III)

Gurantor departmentDepartment of TelecommunicationsCredits5
Subject guarantorIng. Jan Látal, Ph.D.Subject version guarantorIng. Jan Látal, Ph.D.
Study levelundergraduate or graduateRequirementChoice-compulsory type A
Study languageCzech
Year of introduction2021/2022Year of cancellation
Intended for the facultiesFEIIntended for study typesFollow-up Master
Instruction secured by
LoginNameTuitorTeacher giving lectures
LAT04 Ing. Jan Látal, Ph.D.
VAS40 prof. RNDr. Vladimír Vašinek, CSc.
Extent of instruction for forms of study
Form of studyWay of compl.Extent
Full-time Credit and Examination 3+2
Part-time Credit and Examination 8+12

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

Experimental work in labs


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:

Senior,J.M.: Optical fiber communications - principles and practise. Prentice Hall Inc., 2. vydání, 1992, ISBN 0-13-635426-2; Ghatak,A.K., Thyagarajan,K.: Introduction to fiber optics. Cambridge University Press, 1.vydání, 1998, ISBN 0-521-577853; Agrawal,G.P.: Fiber optic communication systems. J.Wiley and Sons, 1. vydání, 1992, ISBN 0-471-54286-5 Papen, G.C., Blahut,R.E.: Lightwave Communications. Cambridge University Press, 2019, ISBN 978-1-10842756-2

Recommended literature:

Filka,M.: Optoelectronics for telecommunications and informatics. ProfiberNetworking CZ,s.r.o., ISBN 987-80-86785-14-1

Way of continuous check of knowledge in the course of semester

Passing two tests in exercises, submission of protocols from laboratory exercises • Written and oral examination


Other requirements

The condition for granting the credit is the submission of all protocols in the laboratory exercise and successful completion of two tests in the exercise. • Written and oral examination


Subject has no prerequisities.


Subject has no co-requisities.

Subject syllabus:

1.Sources for optical communications - advanced description I - Conditions for light amplification, population inversion-description, population inversion and methods of its achievement, three-level and four-level systems, optical feedback, processes in optical resonator, threshold condition for amplification in active laser environment , laser resonator losses, total gain and inversion of the population, gain coefficient of small signals 2. Sources for optical communications - advanced description II - Efficiency of laser diodes - internal, external, differential, power, resonator, threshold amplification and spectral line width, radiant and non-radiative recombination and their influence on LD efficiency, conditions of high efficiency of laser diodes (LD ) on PN junction, function of heterostructures, description of LD efficiency in Ek diagram, characteristics of laser diodes, threshold current LD, spectral properties of LD, shape of radiant trace LD, transverse and longitudinal modes of laser radiation, modulation of LD 3. Sources for optical communications - advanced description III - Theoretical modulation rate LD, analog and digital modulation LD, velocity (modulation) equation LD, relaxation oscillation LD, response LD to unit current jump, intensity modulation LD, chirp LD, noise of laser diodes , RIN and its description, modules of optical transmitters, block diagram of transmitter, LD control circuits, influence of line codes on transmission speed LD, circuit solution of output stages of optical transmitters with LD and LED 4.Sources for optical communications - advanced description IV - Stabilization of working current, stabilization of optical power, light coupling LED-optical fiber, light coupling LD-optical fiber, LD protection against backlight, integral characteristics of optical transmitter-eye diagram, errors in optical design transmitters and their expression in the eye-diagram, internal and external signal modulators, Mach-Zehnder modulator, electroabsorption (Franz-Keldyš) modulator 5. Detectors and receivers for optical communications - advanced description I - SNR and error rate of the receiver, photodiode noise sources, shot noise, thermal noise, dark current, 1 / f noise, photodiode noise equivalent circuit, total noise, standardized noise value, SNR PIN photodiodes, SNR APD photodiodes, dependence of SNR on APD gain, noise equivalent power of photodiode (NEP), BER transmission error, transmission error and decision threshold, error function (erf), complementary error function (erfc) 6. Detectors and receivers for optical communications - advanced description II - Description BER-parameter Q, connection of BER and SNR, error rate expressed by parameter Q, minimum detectable power of photodiode, connection of error rate and minimum detectable optical power, minimum number of photons per 1 transmitted bit , the quantum limit of the received number of photons 7.Receivers for optical communications Block diagram of optical receiver, receiver input part, circuit solution of photodiode-preamplifier circuit, quantizer, time synchronization circuits, decision level circuit, catalog data and parameters of optical receivers 8. Elements of fiber optic networks I - Point-to-point optical connections, fiber optic networks, TDM and WDM, incorporation and separation of channels, signal regenerators in optical networks and signal amplifiers, passive and active elements of fiber optic networks, transmitters for fiber optic networks , requirements for WDM network transmitters, tunable lasers, receivers for optical networks, requirements for WDM network receivers, amplifiers in optical networks, functions of optical amplifiers according to network location, principle of semiconductor optical amplifier (SOA) operation, advantages and disadvantages of SOA 9. Elements of fiber optic networks II - Fabry-Perot amplifier (FP), pass-through amplifier (TW), FP amplifier gain, TW amplifier gain, gain saturation, FP amplifier bandwidth, TW amplifier bandwidth, crosstalk between channels, polarization dependent amplification, noise of optical amplifiers, spontaneous emission amplification, catalog data and parameters of semiconductor optical amplifiers 10. Elements of fiber optic networks III - Erbium fiber amplifiers (EDFA), principle of amplifier operation, energy band diagram, amplifier pumping, C-band and L-band, amplification and noise of EDFA, elements of EDFA modules, connection of erbium doped fibers, methods of reduction losses in connections, EDFA pump diodes, catalog data and EDFA parameters, other types of optical fiber network amplifiers 11.Passive elements of fiber optic networks I - Bidirectional coupling fiber optic couplers, coupler split ratios, characteristics of WDM couplers, catalog parameters and values ​​of fiber optic splitters, micro-optical and waveguide couplers, coupling length, phase mismatch of couplers , WDM multiplexers and demultiplexers, wideband and narrowband WDM 12.Pasivní prvky vláknově optických sítí II - Mux/Dmuxy, WDM vlnovodné mřížky, WDM difrakční mřížky, vláknově optická Braggovská mřížka, užití WDM Muxů a DMuxů ve vydělovačích svazků a routerech, filtry, tenkovrstvé filtry, rezonátorové filtry, laditelné filtry, akustooptické filtry, optické izolátory, cirkulátory a útlumové články, proměnné atenuátory, katalogové parametry a údaje, optické spojovače a přepínače, optické maticové přepínače, konvertory vlnových délek 13.Vláknově optické systémy a sítě I – Analogové systémy, přímá intenzitní modulace, plánování systému, intenzitní modulace subnosné, intenzitní modulace se dvěma postranními pásmy, frekvenční modulace, fázová modulace, PAM, multiplexní strategie 14.Vláknově optické systémy a sítě II – Koherentní a fázově modulované systémy, principy koherentní detekce, modulační formáty, demodulační principy, diferenciální fázová modulace, ASK, FSK, PSK heterodynní detekce, ASK a PSK homodynní detekce, interferometrická přímá detekce DPSK, systémy s více nosnými, polarizační multiplex

Conditions for subject completion

Full-time form (validity from: 2021/2022 Winter semester)
Task nameType of taskMax. number of points
(act. for subtasks)
Min. number of pointsMax. počet pokusů
Credit and Examination Credit and Examination 100 (100) 51
        Credit Credit 45  25
        Examination Examination 55  26 3
Mandatory attendence participation: Optional lectures, seminars have a mandatory attendance of 80%.

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Conditions for subject completion and attendance at the exercises within ISP: Attendance at lectures is optional, the conditions for passing the course are the same as for full-time study, participation in exercises is at least 80%.

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Occurrence in study plans

Academic yearProgrammeBranch/spec.Spec.ZaměřeníFormStudy language Tut. centreYearWSType of duty
2024/2025 (N0714A060020) Communication and Information Technology OKS P Czech Ostrava 2 Choice-compulsory type A study plan
2024/2025 (N0714A060020) Communication and Information Technology OKS K Czech Ostrava 2 Choice-compulsory type A study plan
2023/2024 (N0714A060020) Communication and Information Technology OKS P Czech Ostrava 2 Choice-compulsory type A study plan
2023/2024 (N0714A060020) Communication and Information Technology OKS K Czech Ostrava 2 Choice-compulsory type A study plan
2022/2023 (N0714A060020) Communication and Information Technology OKS P Czech Ostrava 2 Choice-compulsory type A study plan
2022/2023 (N0714A060020) Communication and Information Technology OKS K Czech Ostrava 2 Choice-compulsory type A study plan

Occurrence in special blocks

Block nameAcademic yearForm of studyStudy language YearWSType of blockBlock owner

Assessment of instruction

2023/2024 Winter