Optical writing of channel waveguides and 1D diffraction gratings in photorefractive surface layers of lithium niobate

ABSTRACT

Channel optical waveguides and one-dimensional (1D) diffraction gratings are recorded by laser radiation with wavelengths of 450 and 532 nm within lithium niobate surface layers doped with iron and copper. The characteristics of induced elements are studied by light diffraction. The channel waveguides with widths from 40 to 70 μm are formed in lithium niobate sample with consecutive exposure of stripe-shaped areas. Planar 1D diffraction gratings localized at the surface are formed by its exposure through amplitude masks. Their characteristics are studied with light diffraction using the transmission geometry and at total internal reflection of light from the surface.

KEYWORDS:

• Channel waveguide
• diffraction grating
• photorefractive effect
• lithium niobate
• surface doping

Funding

This study was carried out with the financial support of Ministry of Education and Science of Russia (within the tasks N 3.878.2014/K and N 3.1110.2017/PCh of the project part) and Russian Foundation for Basic Research (Grant 16-29-14046).