Laser-induced preferential domain nucleation in hafnium-doped congruent lithium niobate crystal

The focused visible laser-induced preferential domain nucleation effect is investigated in 3 mol% hafnium-doped congruent lithium niobate crystal. The local phase variation is in-situ monitored during laser-induced preferential domain nucleation. The variations of phase distributions are reconstructed by digital holographic interferometry. The nucleation field decreases exponentially with increasing irradiation intensity. The space charge field along the z direction is thought to be an important mechanism for the laser-induced preferential domain nucleation. Laser-induced hafnium-doped congruent lithium niobate crystals appear to be a promising candidate for further development of ferroelectric domain engineering.