Single-Course English 10 ECTS

Fundamentals of fibre-optic communication systems

Overall Course Objectives

To enable the student to
1. Describe physical working principles of components for optical communication systems and list relevant data parameters.
2. Extract component specifications from data sheets needed for designing an optical communication system.
3. Design an optical communication system on the physical layer.
4. Evaluate the expected system performance of a designed system.

Learning Objectives

  • Describe wave propagation in step-index fibres and determine requirements for single-mode propagation, explain cut-off frequency, birefringence, spot size, attenuation and nonlinear optical effects and evaluate the impact on system performance.
  • Explain spontaneous emission, absorption, stimulated emission and amplification and give a theoretical explanation of the rate equations of a semiconductor laser.
  • Describe the structure and function of semiconductor lasers and light-emitting diodes including static and dynamic properties.
  • Describe the physical processes in photodiodes and the structure of optical receivers at block diagram level.
  • Calculate thermal noise, shot noise, signal-to-noise ratio, bit-error rate and sensitivity in relation to the quantum limit for optical receivers.
  • Define bandwidth, saturation, optical signal to noise ratio and noise figure for Raman and erbium doped fibre amplifiers.
  • Evaluate the impact of amplifier gain and noise on total system performance.
  • Explain the working principles of wavelength selective devices and the application of interference and diffraction to perform wavelength filtering and the usage of these in reconfigurable optical add-drop multiplexers.
  • Discuss origin and predict system limitations of crosstalk in wavelength division multiplexed systems.
  • Explain the building blocks of a coherent transmitter and how advanced modulation formats can be generated.
  • Explain the building blocks of a coherent receiver and discuss the impact of noise on coherent detection.
  • Simulate subsystems of fibre-optic transmissions systems and discuss the results.

Course Content

Optical fibres:
Structure, conditions of propagation, attenuation and pulse dispersion.
Optical amplifiers:
Construction, amplification, noise, Raman, EDFA.
Light sources and transmitters:
Device structure, modulation bandwidth and spectral properties.
Photodiodes and receivers:
Device structure, electrical bandwidth, noise and sensitivity.
Coherent communication:
Coherent transmitters and receivers.
Multichannel systems.
Computer simulations of optical transmission.

Recommended prerequisites

34120/31400/10036/34210/34230, Basic experience with Matlab programming.

Teaching Method

26 lectures including problem solving and mandatory computer simulation exercises.



The course 34130 distinguish itself from 34121 by treating the different parts of optical communications systems more in-depth.
This course is the theoretical counterpart of the experimental optical communication system course 34126 and 34129; the courses complement each other.
This course provides the basis for advanced courses in optical communication such as 34153 Physical Concepts in Optical Communication and 34156 Advanced Optical Communication Systems.
For students who previously have been following the course 34361 Optical Networks, this course provides a more in-depth treatment of optics in communication on the physical layer

See course in the course database.





13 weeks




DTU Lyngby Campus

Course code 34130
Course type Candidate
Semester start Week 35
Semester end Week 48
Days Tues 13-17, Fri 8-12

15.000,00 DKK