The increasing demand for ubiquitous and extremely large bandwidth access to the network calls for the wider deployment of optical solutions not only as a mean of direct connection between the users, but also for the interconnections among wireless - thus microwave – systems. Optical devices are therefore becoming key elements in every modern communication system. This Course aims at providing a deep understanding of their working principle, with a clear focus on applications. The acquired knowledge and skills will be useful not only in designing innovative optical telecommunication systems, but also in other rapidly growing areas of Photonics, such as those of optical sensors and of industrial laser machining. The course is taught in English.

At the end of the Course the students are expected to demonstrate the following main points of knowledge: - understanding of the theory, and the experimental evidence in support, which underpin the mathematical models of the main optical devices; - understanding of the main methodologies to analyse the behaviour of the most common optical and optoelectronic components used in communication systems and in other application domains of Photonics; and the following skills: - identification of the strengths and weaknesses of commercial devices; - ability to propose different approaches to design new optical components; - ability to present, in both oral and written forms, a clear and well-structured set of relevant considerations on design assumptions and results; - ability to read, understand and comment technical material about optical devices from books, manuals, data-sheets, and any other source.

Key notions typically learned in basic courses on applied electromagnetism, such as transmission line theory, modes and principle of operation of metallic waveguides, and plane waves.

• Discrete optical devices (2.5 CFU) o Reflection and refraction of plane waves. o Multi-layered dielectric structures. o Application to the design of anti-reflection coating, beam splitters, interferential filters, waveplates, isolators and circulators, etc. • Dielectric waveguides (2.5 CFU) o Analysis of dielectric waveguides. o Modes of optical fibres: propagation in single mode and multimode optical fibres. o Introduction to the fabrication and characterization of guided wave devices. o Examples of devices: couplers, power splitters, fibre Bragg gratings, etc. • Active devices (1 CFU) o Devices in active optical waveguides: fibre amplifiers and lasers. o Main characteristics of laser diodes.

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 analyse the performance of existing commercial devices, the theoretical derivations are aimed at studying real devices. As for the specific of the exercises, they are integrated in the lectures and deal with the design of simple devices covering subject matter described in the preceding lessons. 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.

• Instructor’s notes. • 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 L.A. Coldren, S.W. Corzine “Diode Lasers and Photonic integrated Circuits”, Wiley. o M.Fukuda “Optical Semiconductor Devices” Wiley. o B.E.A. Saleh, M.C. Teich, “Fundamentals of Photonics”, Wiley.

Modalità di esame: Prova orale obbligatoria;

The main aim of the exam is to verify the learning level of the course topics, i.e. the capability to design the passive components that are commonly present in the RF block of an electronic circuits, to perform their critical analysis, to quantify the effects of interferences and to find possible solutions for their reduction. The exam consists in an oral test organized as in the following. - A first part with simple questions to ascertain the understanding of the subjects presented during the Course. - A second part during which students are asked to solve a problem similar to those solved during exercise classes or proposed in the weekly assignments. Students need only to take with them what is necessary to write and the calculator. No books, solved exercises or notes are allowed. The useful formulas are directly added into the problem text. The maximum achievable grade of the oral exam is 27/30. If it is at least equal to 18/30, it is possible to improve the final grade up to 30/30 cum laude with the submission of the assigned exercises (homework) or with extra questions.

Modalità di esame: Prova orale obbligatoria;

The main aim of the exam is to verify the learning level of the course topics, i.e. the capability to design the passive components that are commonly present in the RF block of an electronic circuits, to perform their critical analysis, to quantify the effects of interferences and to find possible solutions for their reduction. The exam consists in an oral test organized as in the following. - A first part with simple questions to ascertain the understanding of the subjects presented during the Course. - A second part during which students are asked to solve a problem similar to those solved during exercise classes or proposed in the weekly assignments. Students need only to take with them what is necessary to write and the calculator. No books, solved exercises or notes are allowed. The useful formulas are directly added into the problem text. The maximum achievable grade of the oral exam is 27/30. If it is at least equal to 18/30, it is possible to improve the final grade up to 30/30 cum laude with the submission of the assigned exercises (homework) or with extra questions.