The student in this course will acquire: • A broad information on the optical properties of the main materials exploited in photonic devices: dielectrics, metals, semiconductors. To this aim, an extensive phenomenological treatment is provided on the Lorenz theory for the dielectric response, on the Drude theory of the metal response, and on the band-to-band interactions involved in the response of semiconductors (absorption, spontaneous emission, stimulated emission), including the qualitative behavior of quantum well structures and the related selection rules. An introductory reminder is also provided on the crystal and electronic properties of the relevant materials. • A detailed knowledge on the principles of operation of active photonic devices, including sources (LEDs, lasers), optical amplifiers (SOAs), electro-optic and electro-absorption modulators, receivers (pin and avalanche photodiodes). • A knowledge of the propagation properties of the main waveguiding structures (dielectric waveguides, plasmonic waveguides) and of the passive optical components (MMI components, coupled mode components). • A knowledge of the aspects related to the integration of optoelectronic devices (hybrid and monolithic). • The ability of evaluate the main properties of active and passive photonic devices through simplified analytical approaches • The ability of applying numerical techniques (e.g. the beam propagation method) to the analysis of complex propagating (active and passive) photonic structures.

The course requires the basic elements of semiconductor physics, electronic devices (in particular, the theory of pn junction) and of electromagnetic fields and electromagnetic wave propagation. Concepts like TE and TM propagation are re-introduced in detail for the photonic case but some basics are required.

• Introduction to the course. Materials for photonics: optical properties of metals, dielectrics, semiconductors (1 CFU) • Passive waveguiding structures: dielectric & plasmonic waveguides, MMI devices. Mode coupling, coupled mode components (1.5 CFU) • Detectors: pin, avalanche, structure of a photonic receiver (1 CFU)) • Modulators: electro-optic effect, electro-optic modulators, electro-absorption modulators (0.5 CFU) • The Beam Propagation Method and BPM lab (0.5 CFU) • LEDs, Semiconductor Optical Amplifiers and LASERs (1 CFU) • SOA/LASER numerical lab (0.5 CFU)

A recorded version (academic year 2020/21) of the course is available.

Beside the lectures, the course includes numerical classroom labs devoted to solving simple problems and numerical CAD labs described in the course topics.

Lectures are covered by a set of powerpoint slides available from the course website. Part of the course subjects (optical properties of semiconductors, detectors, modulators) are covered in detail in: • G. Ghione, ‘Semiconductor devices for high-speed optoelectronics’, Cambridge 2009. Additional reference books are: • L.A.Coldren, S.W. Corzine 'Diode Lasers and Photonic integrated Circuits' Wiley 1995 (Chapters 3 - 6) • K.J. Ebeling, 'Integrated Opto-electronics', Springer-Verlag, 1993 (Chapters 5 and 6); • L.A. Coldren, S.W. Corzine 'Diode Lasers and Photonic integrated Circuits', Wiley 1995 (Chapters 3-6).

Exam: Written test; Compulsory oral exam; Group essay; Group project;

The examination in based on: 1. A written test on theory (2h), consisting in the written answer to a set of open questions; questions are taken verbatim from a set provided already from the beginning of the course in the web site. Questions are divided in groups (both in the set and in the examination) according to the main subjects of the course; typically, two questions per set are proposed; it is suggested to answer at least to a question per set. The theory test aims at assessing the knowledge of the subjects introduced in the course. During the written test, no written material is allowed. 2. One or more (typically two) CAD lab short reports where the student must apply the CAD tools introduced in the lab to a specific problem and discuss the results. 3. A homework, based on the solution of numerical problems (as discussed in the numerical classroom labs and as available in a solved problem set available from the course web site). The purpose of the homework is to test the students' ability to develop computations (often MATLAB or other computational tools are needed) on the basis of the theory. CAD labs and homeworks are group assignments (2-4 people), only exceptionally individual assignments are considered. Groups are typically organized in the second month of the course. 4. A short oral (20 m max) based on the discussion of the written part and if needed of the CAD reports / homeworks. The purpose of the oral is to test the student's ability to explain in a consistent way the subjects treated in the course; subject understanding in its general lines is more important than the knowledge of this or that formula. If some subject areas are missing in the written test the oral part will by trying to cover first those areas. The relative weight of items 1 and 4 is 4/6; the oral test can correct (+/-) the written score. The weight of item 2 and 3 is 1/6 each.

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.

Exam: Compulsory oral exam; Group essay; Paper-based written test with video surveillance of the teaching staff; Group project;

The examination in based on: 1. A written test on theory (1.5h), consisting in the written answer to a set of open questions; questions are taken verbatim from a set provided already from the beginning of the course in the web site. Questions are divided in groups (both in the set and in the examination) according to the main subjects of the course; at least one question per set is proposed. The theory test aims at assessing the knowledge of the subjects introduced in the course. During the written test, no written material is allowed. The written part will be carried out in presence in one or more Virtual Classrooms in series or parallel, if possible within the day and in the time slot of the each call. 2. One or more (typically two) CAD lab short reports where the student must apply the CAD tools introduced in the lab to a specific problem and discuss the results. 3. A homework, based on the solution of numerical problems (as discussed in the numerical classroom labs and as available in a solved problem set available from the course web site). The purpose of the homework is to test the students' ability to develop computations (often MATLAB or other computational tools are needed) on the basis of the theory. CAD labs and homeworks are group assignments (2-4 people), only exceptionally individual assignments are considered. Groups are typically organized in the second month of the course. This strategy may be changed if the course is offered in remote. 4. A short oral (20 m max) based on the discussion of the written part and if needed of the CAD reports / homeworks. The purpose of the oral is to test the student's ability to explain in a consistent way the subjects treated in the course; subject understanding in its general lines is more important than the knowledge of this or that formula. If some subject areas are missing in the written test the oral part will by trying to cover first those areas. The oral will be in a Virtual Classroom according to a schedule to be specified after the written test. Note that the written test plus oral may be replaced by a longer individual oral where the student is asked first to discuss questions taken from the list. The total relative weight of items 1 and 4 is 4/6; the oral test can correct (+/-) the written score. The weight of items 2 and 3 is 1/6 each.

Exam: Written test; Compulsory oral exam; Group essay; Paper-based written test with video surveillance of the teaching staff; Group project;

The examination in based on: 1. A written test on theory (1.5h), consisting in the written answer to a set of open questions; questions are taken verbatim from a set provided already from the beginning of the course in the web site. Questions are divided in groups (both in the set and in the examination) according to the main subjects of the course; at least one question per set is proposed. The theory test aims at assessing the knowledge of the subjects introduced in the course. During the written test, no written material is allowed. If the exam is taken in remote, the written part is carried out in presence in one or more Virtual Classrooms in series or parallel, if possible within the day and in the time slot of the each call. 2. One or more (typically two) CAD lab short reports where the student must apply the CAD tools introduced in the lab to a specific problem and discuss the results. 3. A homework, based on the solution of numerical problems (as discussed in the numerical classroom labs and as available in a solved problem set available from the course web site). The purpose of the homework is to test the students' ability to develop computations (often MATLAB or other computational tools are needed) on the basis of the theory. CAD labs and homeworks are group assignments (2-4 people), only exceptionally individual assignments are considered. Groups are typically organized in the second month of the course. This strategy may be changed if the course is offered in remote. 4. A short oral (30 m max) based on the discussion of the written part and if needed of the CAD reports / homeworks. The purpose of the oral is to test the student's ability to explain in a consistent way the subjects treated in the course; subject understanding in its general lines is more important than the knowledge of this or that formula. If some subject areas are missing in the written test the oral part will by trying to cover first those areas. If the exam is taken in remote the oral will be in a Virtual Classroom according to a schedule to be specified after the written test. Note that the written test plus oral in the Virtual Classroom may be replaced by a longer individual oral where the student is asked first to discuss questions taken from the list. The total relative weight of items 1 and 4 is 4/6; the oral test can correct (+/-) the written score. The weight of items 2 and 3 is 1/6 each.