Comparative study of nonlinear-optical polymers for guided-wave second-harmonic generation at telecommunication wavelengths

Tomas, Pliska, Wook-Rae Cho, Joachim Meier, Anne-Claire Le Duff Vincent Ricci, Akira Otomo, Michael Canva, and George I. Stegeman Paul Raimond and Franqois Kajzar


Abstract
We report on the linear and nonlinear-optical properties of 4-dimethylamino-4'nitrostilbene (DANS), 4-diethylamino-nitrobenzy1 (DANB), and 4- [N-ethyl - N - (2- hydroxyethyl) amino - 4'- nitroazobenze) (Disperse Red 1;DR1) side chain polymers whose second-harmonic generation at the telecommunication wavelength of 1.55 m was investigated. Measured ultraviolet- visible- near- infrared spectra were analyzed with an inhomogeneously broadened line-shape model, in particular, in the long-wavelength tail of the electronic transitions, which determines the absorption loss at the second-harmonic wavelength. The nonlinear-optical coefficients were measured at different poling temperatures and poling fields by the Maker fringe technique. On the basis of the measured material parameters we calculated the normalized conversion efficiencies for guided-wave second-harmonic generation at 1.55 m. The DR1 polymer exhibited the best nonlinearity-absorption trade-off, with a calculated normalized conversion efficiency of several hundred percent per watt, whereas the figures of merit for DAMS and DANS are lower and comparable with each other.