Optical LiNbO_3 3-branched waveguide and its application to a 4-port optical switch

Abstract

An optical multimode 3-branched waveguide in Ti-diffused Z-cut LiNbO₃ is discussed experimentally and theoretically. The guided light was selectively fed into three branches with the extinction ratio of nearly 10 dB at an applied voltage of V₀ = ±25 V. As an example of the applications, we propose a 4-port optical switch which consists of 3-branched waveguides and bent waveguides. The bent waveguide with a 0.5-mm radius of curvature was fabricated in Nb₂O₅/Ti:LiNbO₃.