8B-218-PHO - Non-linear Optics

COURSE OBJECTIVES :

This course is an introduction to nonlinear optical interactions that occurs when an optical beam at high intensity propagates through a material medium. In a nonlinear regime, the response of the medium is no longer proportional to the amplitude of the excitation field. In a perturbative regime, the nonlinear response of the material is then described as a power expansion of the applied electromagnetic field, related to the so-called 2^nd, 3^rd… order nonlinearities. Nonlinear interactions between a field and a material medium give rise to a wide variety of phenomena and applications: generation of 2^nd, 3^rd harmonic for the doubling (even tripling) the frequency of a laser beam, parametric amplification and oscillation with the realization of widely tunable coherent oscillators (OPO), generation of frequency comb, supercontinuum sources, self-phase modulation effects, self-focusing or de-focusing of beams...

Starting from basic concepts in electromagnetism, the course will focus on introducing useful tools for understanding the basic concepts of nonlinear optics, for deriving standard models to describe the mostly used nonlinear interactions (2^nd and 3^rd orders), and finally for evaluating the efficiency and order of magnitudes in specific cases.