THE PHOTOINDUCED ANISOTROPY OF 2ND-HARMONIC GENERATION IN MONOLAYEREDLANGMUIR-BLODGETT-FILMS

Photoinduced anisotropy of non-linear optical properties of Langmuir-B lodgett films of 4-nitro-4'-octadecilazobenzene has been studied for t he first time by means of second harmonic generation. It was shown tha t the anisotropy of second order susceptibility of the films could be controlled by illuminating them by polarized visible CW radiation. The primary non-linear susceptibility corresponded to the direction perpe ndicular to the polarization vector of the CW radiation. These transfo rmations of the films were reversible and could be repeated many times . Possible mechanisms of such a reconstruction of the films are discus sed.