Traveling Wave Electrode Design for a LiNbO3 Integrated Optical Switch

Integrated array optical switch puts forward higher requirements for switch time and switch voltage. In order to achieve lower switch voltage and shorter switch time, the theoretical model of coplanar waveguides (CPW) electrode is established for Lithium niobate (LiNbO3) optical switch, and a novel structure with thickening buffer layer between electrodes is proposed in this paper. Then the modulation bandwidth and electro-optic overlap integral are qualitatively analyzed and optimized by finite element method (FEM). The simulation results show that the electro-optic overlap integral increases gradually with the raising of buffer layer thickness between electrodes. The switch voltage of the optical switch is about 5.7V, which is lower than the traditional electrode structure. The switch time is about 0.48ns. This new structure contributes to reducing the half-wave voltage of the modulator and can be potentially used in the field of electro-optic modulation.