Proton exchange (PE) offers a simple alternative to titanium indiffusion as a method of fabricating waveguides in LiNbO3.1 PE waveguides are desirable for device applications because of their polarization selectivity and immunity to optical damage.2 Also, the relatively cool PE waveguide fabrication temperature, 200-400°C, allows integration of PE devices into LiNbO3 crystals containing titanium waveguide devices. For many practical applications, PE waveguides will require low Insertion loss when coupled to other waveguides such as fibers or titanium waveguides in the same crystal. Here we report on PE waveguides in z-cut γ-propagating LiNbO3 for 1.32-μm TM polarized light that have low insertion loss when coupled to a fiber. We also report on a low- loss TM-pass polarizer in z-cut LiNbO3.
© 1987 Optical Society of AmericaPDF Article