Degree in Computer Engineering

Study Computer Engineering at La Salle and become a professional with the abilities to work with the latest technologies and new products, designing, implementing and maintaining computer systems for any sector of economic activity

Optical Communications

This subject focuses in studying the optical fiber communications components and systems. Students will learn how the light is propagated through the optical fiber and to design an optical-communication link considering the limitations that affect the transmission environment. Moreover, students will also learn to choose the fitting components taking into account their functional characteristics within an optical communication network. Finally, the principal kinds of communication networks will be studied.
Type Subject
Previous Knowledge

Physics, electromagnetism and electromagnetic propagation basis.


Students graduated of the course of optical communication acquire the knowledge and develop the skills listed below:

1. The student acquires knowledge that gives him a solid basis to face complex designs of optical fiber links.
2. The student consolidates the most general concepts about optical communication which makes possible to study deeper this subject and to carry out research works.
3. The approach of the subject helps the student to develop his capacities of learning and search for information.
4. The student is aware of the latest trends in optical-communications components, which imply a permanent training in these topics.


1. Introduction to optical communications.
1.1 Evolution of optical communications.
1.2 Optical communication systems.
1.3 Optical fiber characteristics.
2. Principles of optical fiber.
2.1 Ray optics basics.
2.2 Classic effects of optical-fiber-communications limits.
2.3 Optical fiber and fabrication techniques.
3. Light propagation through optical fiber. Electromagnetic optics.
3.1 Light-propagation analysis.
3.2 General equation for optical fiber propagation.
4. Design and calculus of optical fiber links.
4.1 Attenuation and dispersion.
4.2 Optical-fiber nonlinear systems.
4.3 Other limiter effects.
5. Interferometry and coupling-based components.
5.1 Optical coupling.
5.2 Circulators and isolators.
5.3 Optical filters.
6. Transmitters and receivers for optical communications.
6.1 Interaction between photons and atoms. Rate equations.
6.2 Lasers.
6.3 LEDs.
6.4 Light detection diodes.
7. Optical amplifiers.
7.1 Introduction.
7.2 EDFA.
7.3 PDFA.
7.4 SOA.
7.5 Raman amplifiers.
8. Wavelength commuters and converters.
8. 1 Optical switches.
8.2 Wavelength converters.
9. Typology of optical networks and communications.
9.1 Broadcast&select networks.
9.2 Networks with wavelength routing.
9.3 Recovering in failures.


The methodology is based in lectures. Slides are used to help students to understand the teacher´s explanations. These slides are available before each session so students can take notes in them during classes. After each theme and before each exam, some classes are dedicated to solve problems related with the subject.

If a student has doubts about the subject, he can send an e-mail to the teacher to set an appointment for clarifying concepts, solve questions, offer exercises, etc.

The student has the following responsibilities after class time:
1. Search for complementary documentation if he wants to extend specific aspects studied in class. The information can be searched in the suggested bibliography and the student may ask the professor for the most interesting books according the personal objectives.
2. Study individually or in groups the themes applied in class. They may use the complementary bibliography, but with the concepts explained in classes is enough to understand the assignment.
3. Solve individually or in groups the proposed problems from last-years exams. The students must solve the problems by themselves, and just in case that he/she doesn´t know how to pose the problem after thinking it carefully, he/she may ask for his classmates´ opinion in the forum.


A. Exams

Exams may have any of the following formats, or may be a mixing between them:
1. Theory: theoretical questions about the concepts studied in class that the students shall explain.
2. Problems: The pose of the problems is asset based in the student´s knowledge and the obtained result. The interpretation made by the student about the results is also taken into account.
3. Test: questions with several possible answers about the studied concepts are posed. The student shall choose the correct answer.

B. Continuous evaluation.

Evaluation Criteria

Objective 1:
- The student shall demonstrate the ability to solve complex problems about the design of optical fiber links.
Objective 2:
- The student shall demonstrate that is capable to make a careful study of the subject matter and explain one of the themes studied in class or one completely new.
Objective 3:
- The student shall demonstrate that is capable to boost his capacity to learn and search for information.
Objective 4:
- The student shall demonstrate that he is able to continue his training by being interested in the last trends.

Basic Bibliography

- Comunicacions òptiques. Guia d'estudi. Simó Graells . ISBN: 978-84-9984-014-7
- Sistemes de telecomunicacions. Guia d'estudi. Simó Graells, Ricard Aquilué, Pere Vidal. ISBN: 978-84-9984-006-2
- Optical Networks: A Practical Perspective (Morgan Kaufmann Series in Networking) Rajiv; Sivarajan, Kumar N. Ramaswami. ISBN-13: 978-0123740922
- Fundamentals of Photonics (Wiley Series in Pure and Applied Optics). Bahaa E. A. Saleh, Malvin Carl Teich. ISBN-13: 978-0471358329

Additional Material

- Nonlinear Fiber Optics, Fourth Edition (Optics and Photonics). Govind Agrawal. ISBN-13: 978-0123695161
- Fiber-Optic Communication Systems (Wiley Series in Microwave and Optical Engineering). Govind P. Agrawal. ISBN-13: 978-0470505113