The course presents the principles of laser operation in relation to specific systems and materials. The aim is to provide students with the knowledge necessary to understand and make the best use of the most common types of lasers in their professional careers, and to grasp their technological evolution. In particular, the approach to solid-state laser design is explained with concrete examples. This field currently employs most professionals involved in the design of sources or the optimisation of their industrial applications. Finally, the main applications of industrial lasers and the rapidly emerging applications of ultra-fast sources are discussed.
Course Prerequisites
Principles of electromagnetic theory, geometric and wave optics, optical and optoelectronic components.
Teaching Methods
Lectures (hours/year in lecture theatre): 45 Practical class (hours/year in lecture theatre): 0 Practicals / Workshops (hours/year in lecture theatre): 0
Assessment Methods
The examination consists of an oral test lasting approximately 30 minutes, with discussion of an assigned project (different for each student) prepared by the student over a period of 2-3 weeks prior to the agreed examination date. During the oral discussion, this may serve as a starting point for questions on general concepts presented in the course that are relevant to the project in question.
Texts
Lectures notes: visit KIRO website (A. Agnesi) Further readings: O. Svelto: Principles of Lasers, Springer, New York, 2010
Contents
· Continuous-wave laser oscillator: 4-level and quasi-3-level systems. Factors determining threshold and efficiency. · Optical resonators: Gaussian beams and ABCD formalism. Stable resonators. Spatial quality. Unstable resonators. · Emission spectrum control techniques. · Types of lasers of significant technological importance: Solid-state lasers. Fibre lasers. Electrically and optically pumped semiconductor lasers. Overview of other lasers (CO2, excimer, etc.). · Nanosecond and sub-ns pulsed operating regimes: Low-frequency Q-switching and high-frequency behaviour. Gain-switching. Cavity dumping. Switching devices. Mode locking: techniques and devices. Stability criterion for passive cw-ML. Propagation in dispersive media with Kerr nonlinearity. Ultrashort pulse source technologies (ps/fs). · Ultrashort pulse measurement techniques. · Examples of solid-state laser design in continuous and Q-switching modes. · Continuous and pulsed power amplifiers. · Solid-state sources equipped with frequency converters: harmonics, parametric generation and Raman. · Industrial applications of power lasers: marking, cutting, welding, drilling, trimming, surface treatments. · Industrial and biomedical applications of ultrashort pulses: micromarking, eye surgery, nonlinear microscopy.
