Optimization of multi-function integrated optics chip fabricated by proton exchange in LiNbO3

Abstract

ABSTRACT Multi-function integrated optics chips consisting of a linear polarizer, phase electro-optic modulators and Y-branching power divider were fabricated in x-cut LiNbO 3 wafers with the aid of annealed proton exchange technique. Insertion losses, power transfer coefficient, splitting ratio and its spectral dependence were measured for Y-branching power dividers of different branching topologies based on channel waveguides. The parasitic spectral selectivity and photorefractive damage were suppressed by optimization of branching topology, introducing an extra taper with variable parameters. Keywords: lithium niobate, proton exchange, optical waveguide, power divider, photorefractive damage. 1. INTRODUCTION Optical channel waveguides in lithium niobate are very useful elements for building a variety of integrated optical components. For example, the key component of fiber optical gyroscope (FOG) is the multi-function integrated optics chip (MIOC), which is an important part of the Sagnac interferometer