2ND-HARMONIC GENERATION IN LANGMUIR-BLODGETT-FILMS OF A NUMBER OF AZOBENZENE DERIVATIVES

Second-harmonic generation was used in an investigation of the quadrat ic optical susceptibilities and of the structure of Langmuir-Blodgett films of a number of azobenzene derivatives, The angular distribution of second-harmonic radiation could differ significantly for films cont aining domains with the average size r considerably less than the seco nd-harmonic wavelength lambda and films consisting of relatively large domains (r much greater than lambda). The orientation of the molecule s relative to the substrate was determined in both cases.