  We reported on a graphical domain engineering technique with the capability
to fabricate macroscale domain structures with nanoscale spatial resolution in
non-polar-cut lithium niobate thin film on insulators through the biased probe
tip of scanning atomic force microscopy. It was found that the domain writing
process is asymmetric with respect to the spontaneous polarization Ps even
though the tip-induced poling field is mirror-symmetric. Various domain
structures, with a dimension larger than millimeters while consisting of
nanoscale domain elements and with arbitrary domain-wall inclination angle with
respect to Ps, were designed graphically and then written directly into
non-polar-cut lithium niobate crystals. As a proof of principle demonstration,
periodically poled x-cut lithium niobate thin film on insulators with a period
of 600 nm, a depth of 460 nm and a length of ~1 mm was fabricated. This
technique could be useful for device applications in integrated optics and
opto-electronics and domain-wall nanoelectronics based on lithium niobate on
insulator.
