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

摘要

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 degrees C with up to 50 heating/cooling cycles resulted in weak changes of SHG performance and domain structure, while annealing at 1000 degrees 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.