Deterministic beam fanning in Fe-doped stoichiometric lithium niobate crystals

We investigated the beam-fanning effect in Fe-doped stoichiometric lithium niobate (Fe:SLN) crystals that were grown by the top-seeded solution growth method. Deterministic beam fanning (DBF) was measured in Z-cut Fe:SLN crystal for incident light propagating along the c+ and caxes. The dependence of beam-fanning factors on incident power density was also studied. The experimental results of DBF in the Z-cut Fe:SLN crystal were in good agreement with a theoretical simulation based on a two-wave mixing model. The results compared with those for Fe-doped congruent lithium niobate crystals indicate that the beam-fanning process in Fe:SLN is deterministic because of its much-reduced intrinsic density of defects.