Lithium Niobate Polarization Splitter Fabricated Using One-Step Diffusion

Polarization splitters with zinc-nickel and gallium indiffusion optical waveguides fabricated on Z-cut lithium niobate substrates are presented. The device fabrication process needs only one diffusion step and, therefore, is greatly simplified. Experimental results show that, at 1.55-μm wavelength, the extinction ratios for the TE and TM modes are 27.8 and 24.5 dB, respectively.