Polarization-dependent optical engineering of ferroelectric domains

Ferroelectric domain engineering with infrared femtosecond laser pulses has been a powerful technique to achieve a spatially modulated second-order nonlinear coefficient in three dimensions. However, studies regarding the influence of laser writing conditions on the light-induced ferroelectric domain inversion remain limited. Herein, an experimental study to reveal the role of laser polarization in light-induced domain inversions is discussed. The dependence of the optical threshold and maximal writing depth of inverted domains on light polarization is experimentally investigated. The results are explained by considering the second-order nonlinear optical properties and birefringence-induced focus splitting in the crystal. These findings are useful in fabricating high-quality and large-scale ferroelectric domain structures for applications in optics, electronics, and quantum technologies.