Crosslinkable organic glasses with quadratic nonlinear optical activity

In this paper, the use of a pure benzimidazole based dimethacrylic push–pull chromophore has been investigated for the preparation of thin films exhibiting quadratic nonlinear optical (NLO) properties. To stabilize these NLO properties, the chromophore orientation has been frozen in a noncentrosymmetric arrangement by cross-linking the material using thermal polymerization induced by suitable initiators. The films present a very stable quadratic optical activity up to T = 152 °C with SHG coefficient d33 of 14 pm/V measured at 1.9 μm.