Reflection of the Stripe Domains in Lithium Niobate Crystal Modified by Soft Proton Exchange

Herein, the results of studying the reflection of stripe domains growing during polarization reversal in congruent lithium niobate single crystals modified by soft proton exchange are presented. The in situ optical imaging reveals the stripe domains with growth directions along three equivalent Y crystallographic axes. When the growing domain approaches the standing one, its growth direction changes by 120° to another Y axis. A strong difference of reflection on opposite polar surfaces is revealed: at the Z+ surface it occurs at lower distances through two successive 60° direction changes, while at the Z− it occurs at higher distances by four successive 30° direction changes. The obtained field dependence of reflection distance is attributed to the influence of the partially screened depolarization field in the vicinity of the standing domain. The fitting of experimental data allows to extract the screening efficiency for stripe domain growth. The lower value of reflection distance on the Z + polar surface is attributed to the higher conductivity of head‐to‐head domain walls as compared to tail‐to‐tail ones. The results obtained are important for the further development of domain engineering methods.