66841 - Computational and Laser Methodologies

Academic Year 2019/2020

  • Moduli: Assimo Maris (Modulo 1) Marco Garavelli (Modulo 2)
  • Teaching Mode: Traditional lectures (Modulo 1) Traditional lectures (Modulo 2)
  • Campus: Bologna
  • Corso: Second cycle degree programme (LM) in Photochemistry and molecular materials (cod. 8026)

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 (not for Industrial Chemistry students).

The student learns the basic theoretical tools to study electronic states, their properties and (photo)chemical reaction paths.

Course contents

Industrial Chemistry students following the course of Theoretical and Computational Chemistry M - 4 CFU, will ONLY follow part 2.

Required skills: A basic knowledge of quantum chemistry, spectroscopy and photochemistry is required.

Parts 1 . Laser Methodologies (A. Maris - 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) (this part coincides with the course of Theoretical and Computational Chemistry for Industrial Chemistry students, 4 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 (Photo)Chemistry. The fundamental tools of Computational (Photo)Chemistry 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

Parts 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 and exercises in the classroom for the theory (3 CFU), and computational exercises in the computational laboratory (2 CFU; 1 CFU for the Industrial Chemistry course).

Both experimental and computational lab-activities must be described and discussed in a suitable lab-report (written text or slide presentation). Industrial Chemistry students are not required to produce it.

Assessment methods

Parts 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, with theoretical questions and problems to solve (each one corresponding to a specific maximum score if correctly answered, for a total of 33 points equivalent to a final mark of 30 with Lode). The exam is passed with a minimum score of 18/30.

The final mark for the whole course of Laser and Computational Methodologies is calculated as CFU-weighted average of the Parts 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 (Photo)Chemistry.

Office hours

See the website of Marco Garavelli

See the website of Assimo Maris

SDGs

Affordable and clean energy Responsible consumption and production Climate Action

This teaching activity contributes to the achievement of the Sustainable Development Goals of the UN 2030 Agenda.