Direct writing of ferroelectric domains on the x- and y-faces of lithium niobate using a continuous wave ultraviolet laser

Abstract

Ferroelectric domain reversal has been achieved by scanning a tightly focused, strongly absorbed ultraviolet laser beam across the x- and y-faces of lithium niobate crystals. The domains were investigated by piezoresponse force microscopy. The emergence and width of any domain was found to depend on the scanning direction of the irradiating laser beam with respect to the polar z-axis. Full width and half width domains or no domain formation at all could be achieved for scanning along specific directions. We interpret the results by a direct correlation between the local temperature gradient and the resulting polarization direction.