Characterization of planar waveguides obtained by proton exchange in lithium iodate

Abstract Due to its non-linear optical properties, lithium iodate is commonly used in optical devices. By proton exchange, performed by immersing z -cuts LiIO 3 single crystals in a molten hydrated nitrate salt, we formed a solid solution Li 1− x H x IO 3 layer close to the surface. This modification of the structure increases the refractive index so that a waveguide is created. The index profile obtained by m-lines spectroscopy combined with structure characterization by μ-Raman and X-ray diffraction experiments allows us to describe the diffusion process of hydrogen in LiIO 3 .