Temperature dependence of LiNbO3 dislocation density in the near-surface layer

Density of dislocations in the near-surface layer was investigated in X-cut LiNbO 3 depending on thermal annealing in the temperature range of 400°C-600°C.A dynamic model of randomly distributed dislocations has been developed for LiNbO 3 by using X-ray diffraction.The experimental results showed that the dislocation density of the near-surface layer reached the minimum at the thermal annealing temperature of 500°C, with the analysis being performed when wet selective etching and X-ray diffraction methods were used.We concluded that homogenization annealing is an effective technique to improve the quality of photonic circuits based on LiNbO 3 .The results obtained are important for optical waveguides, LiNbO 3 -on-insulator-based micro-photonic devices, electro-optical modulators, sensors, etc.