Abstract
Dye-doped second-order nonlinear optical (NLO) poly(amic acid) (PAA) and polyimide (PI) thin films were prepared via a newly developed real-time poling vapor co-deposition process. This method would plausibly enable many polymeric materials, including high glass transition ones, to be matrix films and many NLO-active chromophores to be desired dopants for making numerous NLO thin films. The PAA film, after curing at 150 °C, showed a considerable improvement in thermal stability. Fourier transform infrared characterization also revealed that a 23 wt % disperse red 1 doped PI thin film exhibited reasonable second harmonic generation (SHG) characteristics even at relatively low poling fields; that is, the SHG coefficient had increased from 0.8 to 5.8 pm/V for a poling field increasing from 0.01 to 0.1 MV/cm.