Organic low-molar-mass and polymeric liquid crystalline NLO materials

摘要

Abstract: harmonic generation by NLO-active organic chromophores is used to monitor the poling dynamics and temporal stability of three kinds on `guest-host' materials: (1) helical polypeptides, (2) random coil polymers, and (3) smectic thermotropic liquid crystals. In (1) sidechain NLO-active chromophores reorient without changing the polymer backbone, whereas in (2) there is a two stage reorientation, sidechains followed by backbone. For the liquid crystal, (3) the mean field gives rise to a threshold poling potential and the polar chromophore orientation appears to be stabilized by the apolar but anisotropic mesogen orientational order. !9