The electrical and optical properties of the nonlinear optical polymer DR1/PMMA films

The nonlinear optical material DR1/PMMA films were prepared by spin-coating method. The films were poled by constant voltage corona charging, Decay of surface potential was found to be slower at higher aging temperature (or poling) temperatures, The spectra of open-circuit (OC) and short-circuit (SC) TSD (Thermally Stimulate Discharge) were compared. One negative at 70 degrees C and one positive peaks at 100 degrees C were determined in open circuit TSD measurement. Only one negative broad peak appeared in short circuit TSD spectra. The OC first negative originated from the relaxation of polarization in the DR1/PMMA films, the second positive peak was due to the release of space charges. These two kinds of peaks usually emerge in polar materials. It indicated that the space charge was trapped to stabilize the polarization in polar materials. The second nonlinear optical effect and optical absorption in and near visible wavelength range was studied in the samples.