Synthesis and nonlinear optical properties of soluble fluorinated polyimides containing hetarylazo chromophores with large hyperpolarizability

摘要

The novel fluorinated polyimides with side-chain nonlinear optical (NLO) chromophores were synthesized from hydroxyl polyimides, followed by the Mitsunobu reaction with NLO chromophores. Molecular structural characterization for the resulting polymers was achieved by H-1 NMR, FT-IR, UV-Vis spectra, elemental analysis and gel permeation chromatography (GPC). The polymers exhibit excellent solubility in common organic solvents, good film-forming properties, high glass transition temperature (Tg) in the range from 193 to 200 degrees C and thermal stability up to 290 degrees C. The polyimides P1 and P2 containing hetarylazo chromophores with large hyperpolarizability possess a high electro-optic (EO) coefficient (r(33)), which is larger than that of the polyimide P3 attached DR1. Excellent temporal stability and low optical losses in the range of 1.9-2.1 dB/cm at 1.55 mu m were observed for these polymers. Such new NLO fluorinated polyimides are distinguished by an excellent combination of NLO activity, temporal stability, and optical loss.