Lithium-niobate channel waveguide for the realization of long-period gratings

We propose a special lithium-niobate (LiNbO3) single-mode waveguide for the realization of long-period gratings, which consists of a channel core embedded in a thin slab cladding. We fabricated the waveguide on a z-cut LiNbO3substrate with a two-step proton-exchange process and demonstrated its suitability for grating application with a number of removable photoresist long-period gratings deposited on the waveguide surface. The waveguide fabrication process and the LiNbO3waveguide structure could be further explored for the development of electrooptic gratings for high-speed applications.