Bulk periodically poled lithium niobate doped with Yb3+ ions: Growth and characterization

We have obtained ${\mathrm{Yb}}^{\mathrm{3+}}$ -doped bulk periodically poled ${\mathrm{LiNbO}}_{\mathrm{3}}$ crystals grown by adding ${\mathrm{Yb}}_{\mathrm{2}}{\mathrm{O}}_{\mathrm{3}}$ to the congruent melt. The structures obtained have been characterized by scanning electron microscopy, x-ray fluorescence, optical absorption, and second-harmonic generation. About 100 nm of fundamental tunable quasi-phase-matched second-harmonic generation at the pm/V level is obtained in some of the samples.