Zn-Diffused 1 × 2 Balanced-Bridge Optical Switch in a Y-Cut Lithium Niobate

A novel Zn-diffused 1times2 balanced-bridge optical switch fabricated in a y-cut lithium niobate has been proposed and experimentally studied for the first time. According to the experimental results, the highly polarized waveguides with the polarization extinction ratio of about 45 dB and the nondegraded electrooptic r₃₃ coefficient about 30.5 pm/V can be obtained for both wavelengths of 1.32 and 1.55 mum. These encouraging results indicate that the extraordinary-polarized (polarized on the extraordinary axis of the crystal) Zn-diffused waveguides can be potentially applied to the design of an integrated optical circuit being used in the field of fiber-optic gyroscopes and cable television systems.