THE Z-SCAN TECHNIQUE TO CHARACTERIZE NON LINEAR OPTICAL MATERIALS: MODELING AND EXPERIMENT

Abstract

I treat the Z-scan technique applied to characterize a non linear material, probed by a laser beam on one of its atomic transitions. By assuming the caustic of the probing optical beam in accordance with the geometric optics approximation, I model the Z-scan setup. I describe a Zscan experiment I performed in CDTA on a ruby crystal sample with a top hat laser beam from a Nd:YAG laser followed by a second harmonic generator. The experimental and theoretical Z-scan curves, thus obtained, show good agreement. The cubic non linearity in the material sample, ruby, is eventually determined.