The course is taught in English.
This teaching unit offers an in-depth coverage of coherent optics (photonics). This subject deals with the peculiar properties of laser light and is the basis for technological achievements such as fiber optics communication networks ('broad band access'), deformation or pollution optical sensors or devices used for biological investigations. In particular, both free-space and guided-wave propagation of optical fields are addressed. A number of fundamental optical components are described and the relevant design methods are presented.
In addition, the student is exposed to signal-integrity issues of electromagnetic compatibility and quantitative methods are explained to assess such effects in multi-signal transfer structures.
Optical technologies are one of the key technologies for the 21st century applications, as recognized by the European Commission in declaring Photonics one of the Key Enabling Technologies for its driving role in many sectors that span both the industrial value chains and the people’s health and safety.
This course offers an in-depth coverage of the optical components that rely on coherent waves and that are at the basis of some of the most relevant recent achievements, such as optical fiber communications, material processing machines, and optical sensors for civil, industrial, biomedical and environmental monitoring. The aim is to provide a deep understanding of their working principles, with a clear focus on applications. The acquired knowledge and skills will be useful for designing innovative systems for the various rapidly growing areas of Photonics; moreover, many of the discussed approaches and methodologies will be transferable to other domains of applied electromagnetism, such as microwave systems and electromagnetic compatibility.
The course is taught in English.
Knowledge and understanding of the concepts of free-space propagation, scattering from stratified dielectrics, optical fields in anisotropic media and dielectric waveguides.
Ability to analyze and design basic optical components.
Knowledge of Electromagnetic Compatibility (EMC) issues related to signal integrity in high-speed electronics.
Ability to assess cross-talk and signal distortions in the design of multi-signal transfer structures.
At the end of the course the students are expected to demonstrate the following main points of knowledge:
o understanding of the theory, and the experimental evidence in support, which underpin the mathematical models of the main optical devices;
o understanding of the main methodologies to analyze the behavior of the most common optical components used in various application domains of Photonics;
and the following skills:
o identification of the strengths and weaknesses of commercial devices;
o ability to propose different approaches to design new optical components;
o ability to present, in both oral and written forms, a clear and well-structured set of relevant considerations on design assumptions and results;
o ability to read, understand and comment technical material about optical devices from books, manuals, data-sheets, and any other source;
o ability to apply the learned methodologies to other domains of applied electromagnetism, such as microwave systems and electromagnetic compatibility.
• Basic electromagnetic theory
• Plane waves
• Transmission line theory
• General characteristics of guided wave propagation.
Key notions typically learned in undergraduate courses on applied electromagnetism, such as:
o basic electromagnetic theory;
o transmission line theory;
o plane waves;
o general characteristics of guided wave propagation.
Moreover, the solution of the proposed exercises may require some experience with a computational software such a Matlab, Maple, etc.
Free space optics (geometrical optics, gaussian beams, mirrors and lenses, diffractive optical elements) (1CFU)
Analysis and design of stratified dielectric structures (antireflection coatings, periodic structures and Bragg mirrors) (1CFU)
Optical resonators, Fabry-Perot and Mach-Zehnder interferometers (1 CFU).
Crystal optics and interaction with external fields (plane waves in anisotropic media, electrooptic, acoustooptic effects) (1 CFU)
Guided wave optics (slab waveguides, optical fibers, mode coupling, directional couplers) (2 CFU)
Electromagnetic compatibility for high speed electronics (signal integrity, cross talk in multiconductor transmission lines) (2 CFU)
Discrete optical devices (4 CFU)
o Reflection and refraction of plane waves.
o Multi-layered dielectric structures: application to the design of anti-reflection coating, beam splitters, interferential filters, etc.
o Crystal optics and interaction with external fields: application to the design of waveplates, isolators and circulators, modulators, etc.
o Free space optics: Gaussian beams, lenses, diffractive optical elements, etc.
Dielectric waveguides and waveguide based devices (4 CFU)
o Dielectric waveguides.
o Introduction to the fabrication and characterization of guided wave devices.
o Optical fibers: propagation in single mode and multimode fibers.
o Coupled mode theory and application to guided wave devices: couplers, power splitters, fiber Bragg gratings, etc.
As required by the MS program in Electronic Engineering, it will be also highlighted how the learned methodologies can be applied to solve problems in other domains of applied electromagnetism, and specifically in the electromagnetic compatibility for high speed electronics (e.g., cross talk in multiconductor transmission lines).
Exercise sessions are integrated in the lectures. There will be a couple of laboratory sessions covering optical beam propagation and diffraction phenomena. During the course 7-8 homeworks will be assigned, which require the development of simple Matlab programs.
The course includes lectures on the theory, solution of exercises and experimental demonstrations. As the main goal is to provide the background and methods to understand how to design new components and critically analyze the performance of existing commercial devices, the theoretical derivations are aimed at studying real devices. Exercise sessions are integrated in the lectures and deal with the design of simple devices described in the preceding lectures.
Experimental demonstrations are carried out by the instructor or by small groups of students, depending on the availability and the complexity of use of the specific equipment required.
Lecture notes made available through the course website ("Portale della didattica"). Other texts for reference are:
B. Saleh, M. Teich,"Elements of Photonics", Wiley 1991
K.Iizuka, "Engineering optics", Springer 1987
Lecture notes made available through the course website ("Portale della didattica").
To probe further it may be also useful to consult:
o K. Iizuka, “Elements of Photonics” vol. I + II, Wiley.
o R.G. Hunsperger, “Integrated optics: theory and technology”, Springer-Verlag.
o W. Snyder, J.D. Love, “Optical waveguide theory”, Chapman and Hall.
o B.E.A. Saleh, M.C. Teich, “Fundamentals of Photonics”, Wiley.
Modalità di esame: Prova orale obbligatoria; Elaborato progettuale individuale;
Exam: Compulsory oral exam; Individual project;
Oral exam (30-45 minutes) aiming at ascertaining if the expected learning outcomes indicated in section 2 have been reached. The students will run the programs developed in the home-works and will discuss the results on the basis of the theory presented in the course.
Gli studenti e le studentesse con disabilità o con Disturbi Specifici di Apprendimento (DSA), oltre alla segnalazione tramite procedura informatizzata, sono invitati a comunicare anche direttamente al/la docente titolare dell'insegnamento, con un preavviso non inferiore ad una settimana dall'avvio della sessione d'esame, gli strumenti compensativi concordati con l'Unità Special Needs, al fine di permettere al/la docente la declinazione più idonea in riferimento alla specifica tipologia di esame.
Exam: Compulsory oral exam; Individual project;
The exam aims at assessing the knowledge level of the topics listed in the course program acquired by the student and her/his ability to apply the theory to the solution of simple design projects. Following this approach, the exam, which is only oral and usually lasts from 30 to 50 minutes, includes a discussion of the topics presented during the lectures and the presentation of the results of some assignments given during the course. In more detail, the students are offered two grading paths: “medium/high path” and “top path”. For both paths, the oral exam is organized in two moments: a) answering to 4-5 questions taken from a list published on the course web-portal before the exam period; b) critical discussion of the design assignments given during the course and handed-in at the exam. The medium/high path requires the solution of three design assignments, whereas the top path of five design assignments. The maximum mark achievable with the medium/high path is 27/30, while the maximum mark achievable with the top path is 30/30 cum laude.
In addition to the message sent by the online system, students with disabilities or Specific Learning Disorders (SLD) are invited to directly inform the professor in charge of the course about the special arrangements for the exam that have been agreed with the Special Needs Unit. The professor has to be informed at least one week before the beginning of the examination session in order to provide students with the most suitable arrangements for each specific type of exam.