The polarized absorption spectroscopy as a novel method for determining the orientational order of poled nonlinear optical polymer films

Abstract

A novel method for the determination of the order parameter A2 in anisotropic films with ∞ mm-symmetry, such as poled nonlinear optical polymer films, is presented. The order parameter A2 is believed to shed light on the understanding of the poling mechanism. Light with polarization parallel to the plane of incidence is used to study the absorption behavior of thin poled polymer films as a function of the angle of incidence. Moreover, the order parameter of unpoled samples can easily be determined. The results for the order parameter A2 obtained by polarized absorption spectroscopy are in good agreement with corresponding second-harmonic generation measurements.