LASER AND QUANTUM OPTICS

The course is one of the free-choice educational activities of the Bachelor of Science in Engineering Physics and enables the student to gain knowledge and understanding of fundamental and applied concepts in the field of lasers and quantum optics.

The objective of the course is twofold. On the one hand, to provide knowledge of the operating principles of lasers, both from a physical point of view (with elements of quantum optics), and from an engineering point of view, with elements of geometric optics and control theory, applied to the most common types of lasers. On the other hand, to provide the theoretical and experimental foundations of quantum optics, with examples of applications in information engineering.

At the end of the course, students will be able to describe and model the operation of a laser, both from a physical and engineering point of view, and to acquire the basics of quantum optics in the language of Dirac formalism, applying it to experimental realizations.

1. Knowledge and understanding
Knowing and understanding the laws of quantum optics and their importance in the technological development
Understanding the scientific method and its relevance in the study of natural phenomena and in critical thinking
Understanding the importance of scientific culture in the innovation processes of modern technologies

2. Ability to apply knowledge and understanding
Using the necessary mathematics to describe natural phenomena
Applying the laws of quantum optics, in order to arrive at an understanding of the natural phenomena and to reach an organic view of the physical reality

3. Autonomy of judgment
Knowing how to evaluate the logical consistency of the results, both in the case of theory and of experimental data.
Knowing how to recognize errors through a critical analysis of the applied method

4. Communication skills
Knowing how to communicate the knowledge learned using appropriate terminology, both in oral and written ways
Knowing how to interact with the teacher and with course colleagues in a respectful and constructive way, especially during group work

5. Learning skills
Knowing how to take notes, selecting and collecting information according to their importance and priority
Knowing how to be sufficiently autonomous in the collection of data and information relevant to the problem investigated

The course does not formally require having passed previous courses, but takes for granted many of the concepts covered in the courses of Mathematical Analysis 1 and 2 (derivatives and integrals to one and more variables), Linear Algebra (vector spaces and operations between vectors, equations to eigenvalues), Mathematical Methods for Physics and Engineering (Hamiltonian formalism), Physics 1 (classical harmonic motion), Physics 2 (wave equation), from Fundamentals of Telecommunications (Fourier transforms) and Automatics (stability of a system) and Quantum Mechanics (quantum harmonic oscillator and Dirac formalism).

1. Fundamentals of quantum physics and principle of laser operation
Transition probability and matrix elements
Mode structure of space and quantization of the electromagnetic field
Population inversion and feedback
Spectroscopic rate equations

2. Optical resonators
Recalls of geometrical optics
Linear resonators
Mode structure and intensity distribution
Gaussian beam

3. Laser examples and applications
Gas lasers: He-Ne
Solid-state lasers: titanium-sapphire
Generation of short and ultrashort pulses by Q-switching and pulse compression
Basics of fiber optic lasers

4. Electromagnetic field quantization
Single-mode quantization
Multimode quantization
Vacuum fluctuations and zero-point energy

5. Beam splitters and interferometers
Single-photon beam splitter experiments
Single-photon interferometry
Heisenberg formalism
Wave-particle duality and complementarity

6. Applications of quantum optics
Quantum random number generation (QRNG)
Quantum key distribution (QKD)
Quantum entanglement: principle and applications

Eichhorn, Laser Physics from Principles to Practical Work in the Lab, Springer
Gerry and Knight, Introductory Quantum Optics, Cambridge University Press

The achievement of the learning goalsìs is assessed through participation in the activities of the group work, class exercises, a final written exam and an oral exam.

The final written exam consists of problems similar to those carried out in class during group work. The use of notes, books and other teaching material is not allowed during the final assignment. An example of the final assignment will be made available before the final exam.

Students attending the lessons can accumulate additional points by participating in the quizzes and exercises offered in class. The bonus will be added to the grade of the written assignment.

Seminars: limited frontal lecture, group work (peer-teaching, problem solving)
Exercise Sessions: group work (peer-teaching, problem solving)

Italian

written and oral

This subject deals with topics related to the macro-area "Climate change and energy" and contributes to the achievement of one or more goals of U. N. Agenda for Sustainable Development