Visualization of κ₁-phase in proton-exchange waveguides on the surface of lithium niobate crystal

Abstract

This work is devoted to the visualization and evolution of κ₁-phase particles in annealed proton exchange (PE) waveguides. It is well-known that the presence of κ₁-phase particles in optical waveguides leads to an increase in their optical losses and instability of operation. It has been found that precipitated κ₁-phase particles propagate through the whole waveguide depth and have perpendicular orientation to the surface of the lithium niobate crystal. These results are important for fast quality control of annealed PE waveguides.

Keywords:

• Lithium niobate
• waveguides
• phases
• annealed proton exchange

Acknowledgments

The equipment of the Ural Center for Shared Use “Modern nanotechnology” Ural Federal University (reg. no. 2968), which is supported by the Ministry of Science and Higher Education RF (project no. 075-15-2021-677) was used.

Additional information

Funding

This work was supported by RFBR and Perm Territory under grant No. 20-42-596001.