PHOTONICS

The educational objective of the course is to provide students with the fundamentals of photonics - the science behind the emission, control and detection of light quanta - as well as its main applications.

Knowledge and understanding:

Critical understanding of the most advanced developments in Modern Physics both in theoretical and laboratory aspects and their interconnections, also in interdisciplinary fields.

Adequate knowledge of advanced mathematical and computer tools currently in use in the fields of basic and applied research.

Remarkable mastery of the scientific method, and understanding of the nature and procedures of research in Physics.

Ability to apply knowledge:

Ability to identify the essential elements of a phenomenon, in terms of order of magnitude and level of approximation required, and be able to make the required approximations.

Autonomy of judgment:

Ability to argue personal interpretations of physical phenomena, comparing in the context of working groups.

Development of a sense of responsibility through the choice of elective courses and the topic of the degree thesis.

Communication skills:

Ability to communicate in Italian and English in the advanced fields of Physics.

Learning ability:

Ability to acquire adequate cognitive tools for the continuous updating of knowledge.

Ability to access specialized literature both in the chosen field and in scientifically close fields.

Ability to use databases and bibliographic and scientific resources to extract information and ideas to better frame and develop their study and research work.

Ability to acquire, through self-study, knowledge in new scientific fields.

METHOD OF COURSE OF THE COURSE

The course will be carried out through lectures in the classroom.

REQUIRED PREREQUISITES

Notions of: electromagnetism and quantum mechanics are essential. Basic knowledge of semiconductor physics is important.

LESSONS ATTENDANCE

Attendance is compulsory.

The course is structured in two parts. The first part covers the fundamentals of light matter interaction, lasers and waveguides. The second part covers semiconductor-based devices for photonics and optoelectronics as well as fundamentals of electronic and optical transport.

Should the circumstances require full or partial online teaching, appropriate modifications to what is hereby stated may be introduced in order to achieve the main objectives of the course.

Exams may take place online, depending on circumstances.

Light-Matter Interaction

Radiation-Matter Interaction - Absorption, Spontaneous and Stimulated Emission - Rate Equation and Probability - Natural Line Width - Einstein's Treatment of Black Body -

Optical amplification

Population inversion - Basic principles of optical amplification - Gain saturation process - 3 and 4 level systems - Optical gain - Laser - Fabry- Perot cavity - Cavity modes - Finesse

Atomic Lasers

Operation of some specific types of laser: the ammonia maser, the ruby laser, the neodymium laser, the helium-neon laser.

Wave guides

Guides with planar mirrors: guide modes, propagation constant, field distribution, group velocity - Guides in planar dielectrics: guide modes, numerical aperture, field distribution, group velocity - Two-dimensional guides - Optical coupling - Coupling between the guides and switching - Mach Zehnder structures and modulators - optical fibers - attenuation and dispersion - signal re-amplification

Photonic Crystals, Plasmonics and Metamaterials

Basic principles of functioning of a photonic crystal - Nanocavity - Purcell effect - Photonic crystal laser - Quasicrystalline and disordered photonic structures - Plasmonics - Metamaterials - Applications

Semiconductor LED

LEDs with III-V and II-VI semiconductors - Extraction efficiency - Rare earths - Si: Er LEDs - Quantum dots and quantum wires - Nano and heterostructure LEDs

Semiconductor laser

Optical gain in semiconductors - Laser diode - Heterostructure laser - VCSEL - Low-dimensional laser

Pulsed and ultra-fast lasers

Q switching - Mode-locking

Other photonic devices: Photodetectors

Photodetectors - Single photon detectors - Quantum efficiency

Raman scattering and SERS

Electronic and optical transport in disordered materials

Ballistic - diffusive - localization regimes.

1. Saleh & Teich, Fundamentals of Photonics, John Wiley & Sons Inc.
2. O. Svelto, Principles of Lasers, Plenum Press
3. J.D. Joannopoulos, S.G. Johnson, J.N. Winn, R.D. Meade, Photonic Crystals: Molding the Flow of Light, Princeton University Press
4. S.G. Johnson, J.D. Joannopoulos, Photonic Crystals: The Road from Theory to Practice,
5. W. Cai & V. M. Shalaev, Optical Metamaterials. Springer
6. L. Novotny & B. Hecht, Principles of Nano-Optics, Cambridge University Press
7. S. M. Sze, Physics of Semiconductor Devices, John Wiley & Sons Inc.
8. Kluwer V.V. Mitin, V.A. Kochelap, M.A. Stroscio, Quantum Heterostructures: Microelectronics and Optoelectronics.
9. P. Sheng, Introduction to Wave Scattering, Localization and Mesoscopic Phenomena, Springer, New York, 2nd ed.
10. E. Akkermans & G. Montambaux, Mesoscopic Physics of Electrons and Photon, Cambridge University Press