NONCENTROSYMMETRIC LANGMUIR-BLODGETT-FILM OF PHENYLPYRAZINE DERIVATIVE APPLICABLE TO NONLINEAR WAVE-GUIDES

Thick noncentrosymmetric LB films of more than 200 bilayers (thickness of more than 1-mu-m) were successfully fabricated with an alternating deposition of a phenylpyrazine derivative and arachidic acid monolayers. The alternating LB films were transparent from visible to near infrared region. Spectroscopic and X-ray diffraction studies on the alternating LB films proved that molecules were predominantly oriented normal to the film plane in the LB film. Further, the quadratic dependence of second-harmonic (SH) intensity on film thickness was confirmed in the LB films in the wide range of thickness from 1 to 200 bilayers. From the SH generation measurement, the alternating LB films were found to have fairly large second-order nonlinear susceptibility, which was estimated to be 1 X 10(-7) esu.