Novel fluorine-containing second-order NLO polymers with high glass transition temperature

We will report the synthesis and linear and nonlinear optical (NLO) properties of novel fluorine-containing second-order NLO polymers with high glass transition temperature (T_g). Using pentafluorobenzonitrile as a starting material, a monomer with electron-donating group for NLO active site was synthesized. This monomer was polymerized with four types of bisphenol analogues. Three types of electron-withdrawing groups for NLO activity were introduced into the polymers by post-functionalization. These NLO polymers show high T_gs, e.g., a polymer containing fluorene structure has T_g of 209 °C. An NLO polymer with fluorene structure and DR1 at 100 mol% content does not show polarized light dependence of the refractive indices and has very low optical propagation loss of 0.42 dB/cm at 1.3 μm. The polymer has χ⁽²⁾₃₃ value of about 57 pm/V at 1.3 μm fundamental wavelength and the nonlinearity was maintained at 100 °C for more than 160 h. © 2002 Elsevier Science B.V. All rights reserved.