Annealing stability of the domain structure in periodically poled MgO doped lithium niobate single crystals

Abstract

The stability of periodical domain structure during high-temperature annealing was studied in MgO doped lithium niobate single crystals by analysis of efficiency and homogeneity of the second harmonic generation (SHG) signal and optical visualization of the domain pattern. Annealing at temperatures up to 600 °C with up to 50 heating/cooling cycles resulted in weak changes of SHG performance and domain structure, while annealing at 1000 °C resulted in eight times decrease in the average SHG power and two times decrease in the effective periodical domain structure depth. Backswitching was attributed to the action of electric field induced by the crystal composition gradient caused by Li out-diffusion.

Keywords:

• Periodical domain structure
• lithium niobite
• second harmonic generation
• periodical poling
• ferroelectric domains
• lithium out-diffusion

Additional information

Funding

The equipment of the Ural Center for Shared Use “Modern Nanotechnology” Ural Federal University was used. The work was supported by Government of the Russian Federation (Act 211, Agreement 02.A03.21.0006) and by RFBR (grants 17-02-00865 and 18-29-20077-mk). VS and AA are grateful for financial support to the Ministry of Science and Higher Education of the Russian Federation (state tasks 3.4993.2017/6.7 and 3.4973.2017/7.8).