66841 - Computational and Laser Methodologies

Learning outcomes

The student learns the basic principles of Laser operation, knows the optical properties which characterize the Laser radiation and the various chemical applications of the main Laser sources which are commercially available.

The student learns the basic theoretical tools to study excited states, their properties and photochemical reaction paths.

Course contents

Part 1 . Laser Methodologies (C. Degli Esposti - 6 CFU) :

1-Principles of Laser operation.

Stimulated emission, inversion of energy levels population, the pumping processes, optical resonators. The threshold condition in a real laser. Continuous wave Lasers and pulsed Lasers. 3 and 4 levels Lasers. Properties of laser light : directionality, brightness, monochromaticity, coherence. Multi-mode and single-mode laser emissions. Applications of laser light: optical reading, atmospheric remote sensing, laser surgery, high-resolution spectroscopy, Raman spectroscopy, holography.

2-Commercially available Lasers.

The different types of Laser sources and the physical or chemical phenomena which make them work.

Atomic emissions: He-Ne, Ar+ , and Nd3+ lasers.

Molecular vibronic: N2 , excimer, and dye lasers.

Molecular rovibrational: CO2 and HF lasers.

Transition metals doped crystals: ruby and Ti:sapphire lasers.

3-Instrumental techniques.

Non-linear optics for harmonics generation. The creation of ultra short pulses: the Q-switching and mode-locking methods. Spectroscopic, photochemical and analytical applications of pulsed Lasers.

4-Laboratory experiments.

Laser-based experiments : scattering , laser-induced fluorescence , Raman spectroscopy .

Part 2 . Computational Methodologies (M. Garavelli - 5 CFU) :

  The rational is provided for the use and the application of theoretical models (such as PMO, VB-Configuration Mixing, Correlation Diagrams, etc) to the understanding, modeling and prediction of chemical reactivity in Photochemistry. The fundamental tools of Computational Photochemistry are also provided and applied during the laboratory exercises, to solve actual problems of structure and reactivity in Photochemistry, Photobiology and Material Chemistry.

Readings/Bibliography

D. L. Andrews, Lasers in Chemistry, Springer, 3rd edition.

O. Svelto, Principles of Lasers, Plenum Press, 4th edition.

Lowry, T. H.; Richardson K. S., Mechanism and Theory in Organic Chemistry
Sundberg R. J., Carey F. A., Advanced Organic Chemistry
Scientific papers and other specifically prepared material.

Teaching methods

Part 1 (Laser Methodologies ) : Lessons in the classroom (4 CFU) for the theory, numerical exercises in the classroom or in the laboratory (1 CFU), and laboratory activities (1 CFU) where lasers-based experiments are performed.

Part 2 (Computational Methodologies) : Lessons in the classroom (3 CFU) for the theory, and computational exercises (2 CFU) in the computational laboratory.

Both experimental and computational lab-activities must be described and discussed in a suitable lab-report (written text or slide presentation).

 

Assessment methods

Part 1 (Laser Methodologies ) : A single oral examination at the end of the semester. The student must report on three different topics which are part of the teaching program. The total length of the examination is ca. 30 minutes. The written reports on laboratory activities are also evaluated, and they contribute 1/6 of the total mark (from 0 to 5 points over a total of 30).

Part 2 (Computational Methodologies): A single written examination at the end of the semester . Written reports on laboratory activities are also evaluated.

The final mark for the whole course of Laser and Computational Methodologies is calculated as CFU-weighted average of the Part 1 and Part 2 marks.

Teaching tools

Projector for transparencies and slides in the classroom.

Laser instrumentation available in the Department for Laser-based experiments.

Workstations and software packages are used in the Computational Lab to explore and study reaction mechanisms in Photochemistry.

Office hours

See the website of Claudio Degli Esposti

See the website of Marco Garavelli