Two dimensional ferroelectric domain patterns in Yb3+ optically active LiNbO3 fabricated by direct electron beam writing

We report on highly controllable ferroelectric domain inversion in Yb3+ doped LiNbO3 laser crystal. The ferroelectric domain patterns are fabricated by direct electron beam writing without any previous masking process. Square lattices of inverted domains with diameters and distance between domains as low as 1 μm are demonstrated. The lateral growth of the inverted domains is analyzed as a function of the applied charge and the threshold values for domains in the 1–10 μm length scale are determined. Spatially resolved low temperature fluorescence spectroscopy and non-collinear second harmonic generation experiments are also employed to evaluate the optical properties of the system.