Local polarization state observation and third-order nonlinear susceptibility measurements by self-induced polarization state changes method

Abstract

We report on a new method appropriate to the study of the polarization states of the electromagnetic field at the output of nonlinear medium. The novelty here is the measurement of the elliptical parameters of the polarization state field function of the input laser intensity. New relations were found to estimate the local ellipticity e( r) and the local polarization ellipse rotation θ( r) at the output of the medium. In order to check the reliability of the proposed method, we have confronted this one to determine the third-order nonlinear susceptibility tensor components χ xyyx 〈3〉. The comparison between the values obtained by this approach and some previous values from the literature was entirely satisfying. For instance, we have obtained the χ xyyx 〈3〉 (CS 2)=6.5×10 −20 m 2V −2 with a 10% relative error.