Learning objectives
At the end of the course the students will be able to:
− understand the importance of conventional optical fibers as basic components for photonic devices, such as sensors and lasers, with great impact on the market at present;
− understand the importance of photonic crystal fibers, which are still an exciting research subject all over the world, for next generation of photonic devices;
− analyze the properties of optical fibers with an advanced numerical method (finite element method);
− summarize and report the main results of a numerical analysis.
Prerequisites
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Course unit content
During the first part of the course photonic crystal fibers will be illustrated, with a detailed description of their distinguishing characteristics with respect to conventional optical fibers, in particular of the different light guiding mechanisms, which make them particularly suitable for important applications.
Optical fiber lasers will be the subject of the lessons in the second part of the course. Most common configurations, main parameters to characterize the performances and most important present and future applications will be presented in detail.
The last part of the course will be devoted to a thorough study of point and distributed optical fiber sensors, with particular attention to working principles, practical applications, products already available on the market or still subject of intense research worldwide.
Some lessons of the course, mainly devoted to simulation activities, will take place in laboratory.
Seminars could integrate the course programme.
Full programme
− Photonic technologies of 21st century
Standard optical fibers:
- Light guiding mechanism and guided modes
− Single-mode and multi-mode regime, applications
Photonic crystal fibers:
− Photonic crystals and their properties, photonic crystal fibers and their properties
− Light guiding mechanisms and main applications of photonic crystal fibers
Optical fiber lasers:
− Laser working principle, different laser types and their applications
− Configurations, pumping schemes and doping element for optical fiber lasers
− Performances and limits of high-power fiber lasers
− Active and passive fibers for high-power fiber lasers, main applications and role in the market
Point and distributed optical fiber sensors:
− Main characteristics and properties, working principle, classifications, advantages and disadvantages, significant applications of optical fibers sensors
− Intensity-based sensors
− Spectrum-based sensors
− Sensor multiplexing
− Distributed sensors
Numerical simulation:
− Introduction to the Finite Element Method (FEM) and presentation of the main characteristics of the COMSOL Multiphysics software for the simulation of optical fibers and photonic devices
− Numerical simulation of step-index fibers
− Numerical simulations of fibers with low refractive index cladding: dispersion curve
− Numerical simulations of photonic crystal fibers
Bibliography
S. Selleri, L. Vincetti, A. Cucinotta, “Optical and Photonic Components”, Esculapio, 2015
R. Paschotta, “Encyclopedia of laser physics and technology”, Wiley, 2008
E. Udd, “Fiber optic sensors: an introduction for engineers and scientists”, Wiley, 1991
F. Poli, A. Cucinotta, S. Selleri, “Photonic crystal fibers: properties and applications”, Springer, 2007
Scientific papers suggested during the course
Teaching methods
The teaching activities include lessons carried out in a lecture room, using blackboard and pc/projector to show multimedia presentations, videos/images and web pages (30 hours). In addition, laboratory lessons are planned, with simulation activities carried out using the commercial software COMSOL Multiphysics for the analysis of electromagnetic waves at optical frequency propagating in linear and nonlinear media (12 hours).
The slides of the presentations shown during the lessons are weekly uploaded to the Elly web site. The registration to the course is necessary to download the slides.
Please notice that the presentations are considered an essential part of the teaching material. Students who are not attending to the course should periodically check the teaching material and the information provided by the professor on the Elly web site.
Assessment methods and criteria
The learning assessment is made with:
− an oral exam with questions on the topics developed during the lectures, with the aim to verify the learning level of the student. The oral exam is evaluated in the range 0/30;
− an individual report on a numerical simulation activity carried on with COMSOL Multiphisics. This individual activity concerns one of the optical fibers presented during the laboratory lessons. Students can collect the text describing the activity during the last lesson of the course, or later by appointment in the professor’s office. A Word template in .docx is provided to the student, who is encouraged to use it to prepare the report. The .pdf file of the report must be sent by email to the professor no later than three days before the date of the oral exam. The report is evaluated according to accuracy, completeness and clarity, in the range 0/30.
The mark of the oral exam is communicated to the student at the end of the oral test. The mark of the report is announced to the student just after the end of the oral exam. At the same time, the student can view the report with the corrections. The final mark is calculated as the average of the ones obtained for the oral exam and the report, which are both in the range 0/30. The honors are given to the students who obtain the maximum score for both the oral exam and the report.
The online registration to the exam is mandatory and it is possible until three days before the exam date.
Other information
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