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A straightforward electro-optic polymer covered titanium dioxide strip line modulator with a low driving voltage Feng Qiu, Andrew M. Spring, Daisuke Maeda, Masa-aki Ozawa, An electro-optic (EO) modulator composed of an EO polymer/titanium dioxide (TiO2) hybrid waveguide has been designed and fabricated. By using a TiO2 strip line (0.30.3 lm2 cross-section) as the core, the confinement factor in the EO polymer is optimized, thus achieving a high EO activity. The coplanar electrode spacing is tuned to enable an effective poling and a small propagation loss. The measured in-device EO coefficient is 100 pm/V at 1550 nm, with a driving voltage (Vp) 3.2V for the 12 mm-electrode length. The results also predict a possible Vp of 1V in a push-pull MZI structure. The EO activity of the modulator exhibited an excellent temporal stability at 85 C for 500 h due to the high glass transition temperature of the EO polymer and the temperature-insensitive TiO2 strip line. doi: 10.1063/1.4893925 |