Optical directional coupler switch using domain inversion technology

The switching voltage reduction in optical directional coupler switch utilizing alternating Deltabeta is fully analyzed. It is shown that increasing the number of sections in electrode can reduce the switching voltage significantly. But high-speed operation of the switch is limited as the number of electrode-section increases. In this paper, the improvements of above problems are discussed. By the introduction of domain inversion technology in lithium niobate (LiNbO₃), lower switching voltage and high-speed operation of the optical directional coupler switch can be achieved.