Depolarization field mitigated domain engineering in nickel diffused lithium tentalate

We demonstrated a domain reversal mechanism on Z-cut congruent-grown lithium tentalate (LiTaO₃) composed of nickel (Ni) diffusion followed by pulse field poling. Domain nucleation and forward growth were found confined to the  nondiffused regions, where the commonly observed serrated domain fronts in poled LiTaO₃ were absent in this work.  These observations are ascribed to the formation of domain nucleation barrier by the depolarization field and reveal the divergence effect in the ferroelectric spontaneous polarization at the domain boundary due to Ni diffusion. This mechanism simplifies the fabrication of periodically poled LiTaO₃ for second-harmonic generation in the blue spectral regime.