Polarization-dependent coupling in a 1x4 waveguide array in lithium niobate fabricated by femtosecond pulses

Abstract

We demonstrate a 1×4 waveguide array produced by an IR femtosecond laser in z-cut lithium niobate (LiNbO3). The polarization dependence of light coupling in this waveguide structure is experimentally investigated. The coupling constants of the waveguide array are obtained by measuring the ratio of output power of each waveguide for extraordinary rays and ordinary rays, and the variation of coupled power in each waveguide as a function of the waveguide length are demonstrated.