Aim:

This course offers an introduction on laser history and laser theory, as well as an understanding of laser resonators, Gaussian beams and the principles of laser amplifiers.

 

Content:
- Chapter 1: Brief introduction about laser history, coherence properties, main constituents and applications.

- Chapter 2: Laser resonators. The stability of cavities is treated with the ray matrix formalism assuming centered systems and Gauss conditions.

- Chapter 3: Gaussian beams. 
            Properties of gaussian beams (divergence, waist, phase curvature radius) treated using the complex curvature radius.             
            Transformation of gaussian beams (ABCD law), in particular by a lens (waist conjugation formula). 
            Determination of the fundamental gaussian mode parameters as a function of the cavity parameters (case of linear cavities, 
            symmetric cavities, general case)
            Spatial and spectral modes

- Chapter 4: Principles of laser amplifiers
            Laser-matter interaction (Absorption, stimulated emission, spontaneous emission)
            Transition spectral profile, Einstein coefficients, cross sections
            Homogeneous and inhomogeneous spectral broadening
            Population rate equation systems, population inversion (2-, 3-, 4- level systems)
            Amplification coefficient, Gain
            Saturation

- Chapter 5: Introduction to laser theory
            Brief overview about the pumping mechanisms
            Cavity losses, cavity photon lifetime, threshold
            Working conditions in the continuous regime
            Output intensity and optimisation of the output coupler
            Spatial Hole-burning
            single-mode/multimode operation
            Pulsed regimes (Mode locking and Q-switching)


Année: 21/22