• 052548 - PHYSICS OF ULTRA FAST PROCESSES

To provide the basic knowledge necessary for the understanding of the ultrashort light pulse generation mechanisms, their propagation in linear and nonlinear media, their characterization techniques.

To give examples of application of ultrashort pulses to the study of dynamical processes in physics, chemistry and biology. The acquired knowledge will enable the student to work in advanced research

laboratories as well as in high tech companies developing laser sources or using them for applications in micromachining, telecommunications, sensing or biomedicine.

At the end of the course the student will acquire knowledge and understanding of the underlying physics and the technical working principles of ultrashort pulse laser systems.

The student will be able to apply this knowledge and understanding to different scientific and industrial systems using ultrashort pulse lasers and to make judgements

on the design of such systems for applications to spectroscopy, imaging or material processing.

The student will acquire learning skills that will enable her/him to read andvanced, graduate-level textbooks on nonlinear optics and photonics as well as papers on peer-reviewed scientific journals.

1.   Properties of ultrashort laser pulses

• introduction to ultrafast optics;
• linear propagation equation for ultrashort pulses; dispersion and techniques for its compensation;
• nonlinear ultrashort  pulse propagation in second order media; three-fields coupled equations; second harmonic generation, sum and difference frequency generation;
• nonlinear ultrashort pulse propagation in third order media; Kerr effect, nonlinear Schrödinger equation, solitons, self-phase-modulation;
• ultrashort pulse characterization techniques: non-collinear and interferometric autocorrelation, FROG, SPIDER, 2DSI

2.   Ultrashort pulse generation techniques

• mode-locked lasers and passive mode-locking techniques;
• ultrashort pulse amplification, chirped pulse amplification technique;
• optical parametric amplifiers;
• carrier-envelope phase and frequency combs

3.   Applications of ultrashort pulses

• introduction to ultrafast spectroscopy techniques;
• degenerate, two-colour and broadband pump-probe;
• density matrix formalism for the decscription of light-matter interaction;
• four-wave mixing, photon echo and two-dimensional spectroscopy;
• ultrafast processes in metals and semiconductors;
• introduction to femtochemistry and femtobiology.

The course requires basic knowledge of the foundations of classical electromagnetism, quantum electronics (light-matter interaction, principles of lasers) and quantum mechanics.

A good understanding of the topics handled in the course of Photonics I is an important but not necessary prerequisite. 

The evaluation will consist of a written exam (two hours duration) with questions and/or problems covering the topics of the lectures.

The exam will test the depth of understanding by the student of the handled topics, the developed critical skills and

the capabilities to effectively organize the presented material, using a proper lexicon and efficiency and linearity of the discussion.