OPTICAL COMMUNICATIONS A
Learning outcomes of the course unit
Objective of the course is to provide the basic tools and understanding for the design of modern linear fiber-optic communications systems.
Componenti Ottici A
Course contents summary
Historical perspective. Review of fiber propagation. Modal and chromatic dispersion. Limits on OOK systems. Chirp and its effects. Review of lasers and optical amplification. Semiconductor lasers and chirp under direct modulation. External modulators: Mach-Zehnder and electro-absorption. Chirp in external modulators. Erbium-doped and semiconductor amplifiers. The reservoir model. Noise figure. Saturation. Gain dynamics. Gain clamping. Rayleigh backscattering and the need for isolators. Physiscs of photo-detectors. PIN and APD diodes. Mathematical principles of photo-detection. Campbell’s theorems. Types of OOK optical receivers. BER calculation in OOK systems. Quantum and thermal limits. Personick’s formula. Power budget and margins. Penalty with chromatic dispersion and intersymbol interference. Optically amplified detection : Marcuse’s formula. Masurements of Q-factor. Interferometric noise. Optimization of chains of amplifiers. Submarine links: design rules. Pre-emphasis and gain equalizaion.
For more details on lectures, please consult the Instructor’s web site at http://www.tlc.unipr.it/bononi/
 G. P. Agrawal, ``Fiber-optic communication systems'', 3rd ed. Wiley, 2002.
Exam is oral only. The student is required to solve an exercise on the practical design of a given optical communications link.
The student is required to have a pocket calculator, and (if desired) an A4 sheet with useful formulae.
Please contact the instructor to set the date of the oral exam.