Crosslinkable fluorinated hyperbranched polyimide for thermo-optic switches with high thermal stability

A series of fluorinated hyperbranched polyimides (FHBPIs) were synthesized by condensation of a triamine monomer, 1,3,5-tris(2-trifluoromethyl-4-minopheoxy) benzene (TFAPOB) and various aromatic dianhydride monomers with different linear length for application on integrated optical devices. Near infrared absorption measurement shows that it has high transparency in optical communication wavelength region. The glass transition temperature and thermal decomposition temperature were 189 degrees C and 596 degrees C, respectively. According to the atomic force microscopy analysis, the surface roughness of the FHBPI films is 0.208 nm. A classic MachZehnder interferometer thermo-optic switch with single mode waveguide fabricated by FHBPIs represents excellent switching characteristic. The rise time and fall time of this device are 530 mu s for both. (C) 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2012