Domain structure formation by local switching in the ion sliced lithium niobate thin films

The creation of the periodical domain patterns with a submicron period in lithium niobate on insulator (LNOI) wafers is a key problem for nonlinear-optical applications, including second harmonic generation, backscattering optical parametric oscillator, etc. We have experimentally studied the domain formation and evolution during local polarization reversal in Z+ LNOI wafers with a metal bottom electrode. It has been shown that domain growth occurs by the formation of the spikes at the charged domain wall (CDW). The complicated shape of isolated domains with a jagged CDW has been revealed. The obtained weak domain–domain interaction has been attributed to effective bulk screening by charge injection. The revealed dependence of the domain sizes on humidity caused by the adsorbed water layer should be taken into account during periodical poling.