Poling characteristics of guest-host polymer thin films

Several kinds of disperse-dye polymer films of the guest-host system were prepared by spin-coating method. Disperse orange 25 (DO25), disperse orange 3, disperse red 73, and disperse yellow 9 were chosen as nonlinear optical (NLO) active chromophores and polymethylmethacrylate (PMMA), polycarbonate (PC), and polyetherimide (PI) as polymer matrixes. Polymer films were poled by all optical poling or electric corona poling. The glass transition temperature (Tg), absorption spectra, rigidity, NLO properties of polymer films were characterized by means of DSC, UV-IR spectra, microhardness analyses, and NLO measurements. The all-optical poling characteristic of four kinds of NLO chromophores in PMMA matrixes systems has been investigated. DO25/PMMA has largest NLO effect. The possible explanation has been proposed. The relaxation and rigidity characteristics of DO25 doped polymer matrixes with various Tg have been studied by means of corona poling method. It is found that DO25/PI polymer films show best thermal and temporal stability and DO25/PMMA has largest NLO property. Generally, DO25/PC system has optimal tradeoff properties of NLO and stability. In addition, the second-order NLO coefficient and average electro-optic coefficient of 10wt% DO25/PMMA poled by optical poling and corona poling is determined to be around 60 and 34 pm/V, respectively.