Domain engineering in LiNbO3 crystals by e-beam and features of spatial distribution of electric field: Experiment and computer simulation

Domain gratings with different periods were formed on −Z surfaces of lithium niobate using direct electron beam writing (DEBW) at an accelerating voltage of 15 kV. Features of the gratings obtained were compared to computer simulation results of spatial distribution of an electric field for various schemes of e-beam charges disposed near the sample surface. The Monte Carlo method was used to calculate the injection charge distribution. The electrical potential distribution in irradiated samples was determined by the numerical solution of the Poisson equation. The electric field created by the injected charges was calculated both near the surface and by the depth of the irradiated samples. Peculiarities of the field distribution have been found, in which the formation of regular domain gratings is broken due to the proximity of the injected charges. Based on computer simulations and the experimental results of DEBW (at 15 kV), the search for irradiation schemes was carried out to reduce the limitations in grating periods by decreasing the accelerating voltage of electrons up to 10 kV.