LASER PHYSICS
- Overview
- Assessment methods
- Learning objectives
- Contents
- Delivery method
- Teaching methods
- Contacts/Info
Basic notions of electromagnetism and quantum physics.
In other words it is required that students have already attended courses of Electromagnetism and Physics of Matter.
In addition, it is advisable that students have inserted the course of Optics in their learning program and that they have already attended it.
The final examination is an oral one.
The exam consists in at least three questions on the three different parts of the program:
- radiation-matter interaction and the laser dynamics equations,
- resonators, cavities and pumping schemes,
- short and ultra-short pulses generation in lasers
The exam is aimed at verifying that the students are able to give a physical explanation of the laser dynamics, and to describe the fundamental laser dynamics by means of the rate equations.
They should be able to describe how a laser works in different regimes, explaining the requirements and conditions to be met to achieve the different regimes.
They should be able to discuss the different topics learnt, by means of a proper technical language, and to evaluate the main applications of laser physics.
The answers should develop the requested topics, and for each question the student will get up to 10 points. The final score will be the sum of these three points. In the case of maximum score (30), the student will be given a third question for the merit (full mark cum Laude), in order to evaluate the capacity of the student to reason on topics slightly outside the course program, even if tightly connected.
The course is aimed at providing students with concepts and methods to recognize and understand the laser dynamics and the different existing laser regimes. Indeed, Laser Physics is at the basis of different research fields in experimental Optics and the Laser Physics course could be of great interest for students who intend to undertake a research career in the Optics field, but not only, as Lasers are fundamental nowadays for applications in different fields of Physics, such as Laser Micromachining, Biophysics, Medical physics, and even Astrophysics.
At the very end of the course the theoretical approach will be supported by one or two lessons in the ultrafast nonlinear optics laboratory of the Department, in which students will observe different types of laser, in CW but also in the pulsed regime, and will be able to recognize the different parts of the laser systems.
At the end of the course students should be able to:
• give a physical explanation of the laser dynamics
• describe the fundamental laser dynamics by means of the rate equations
• describe how a laser works in different regimes
• explain the requirements and conditions to be met to achieve the different regimes
• critically evaluate the main applications of laser physics to science and technology
• discuss the different topics learnt, by means of a proper technical language
Other skills requested at the end of the course are:
- The capacity of learning and capacity of using data bases and electronics journals
- The achievement of an adequate level of basic knowledge, that will allow the student to deepen in the future specific topics about the course, also by consulting advanced textbooks and specialized journals also in English.
In classroom
- Introduction, spontaneous and stimulated emission, pumping schemes and laser properties
- Radiation-matter interaction: black body theory, spontaneous emission, absorption and stimulated emission, Line broadening mechanisms, non-radiative decay.
- Energy levels, radiative and non-radiative transitions in molecules and semiconductors
- Passive optical resonators
- Pumping processes
- Laser behaviour in continuous regime, Rate equations, 4 level laser and 3 level laser.
- Transient behaviour of the laser: Q-switching, gain switching, model-locking and methods of mode-locking
- Examples of lasers: solid state lasers, dye lasers, semiconductor lasers, gas lasers
- Laser beam properties
- Transformation of laser beams: propagation, amplification, frequency conversion, pulse compression and pulse expansion.
- Chirped pulse amplification technique
- Examples of laser applications
Lectures will be held in classroom.
In the laboratory:
Observation of laser oscillators, mode-locked laser, Q-switched laser, amplified pulsed lasers; Chirped pulse amplification technique. Nonlinear optics effects.
The course is essentially based on lectures, during which the teacher presents the topics by making calculations and supporting all the statements with practical examples (44 hours).
When it is advisable, the teacher will provide students with additional materials, such as articles and reviews.
The last 4 hours will be devoted to the observation of amplified laser systems in the laboratory, with the aim of recognizing the different laser parts. Lasers will also be turned on in order to observe their effective operation, and to generate and observe some nonlinear optics effects.
For further information contact Dr. Ottavia Jedrkiewicz at ottavia.jedrkiewicz@uninsubria.it