Highly optical damage resistant crystal: Zirconium-oxide-doped lithium niobate

Usage of lithium niobate in nonlinear optics is seriously hampered by optical damage, in particular, where high intensity is needed. Doping with magnesium can improve its resistance against optical damage. However, since a rather large dopant concentration is required (more than 4.6 mol % MgO) and since the distribution coefficient is unfavorable, it is difficult to grow crystals of high optical quality. The authors show that by doping with zirconium, one can obtain at the same time a higher resistance against optical damage, a lower doping threshold (only 2.0 mol % ZrO2), a distribution coefficient near 1.0, and a low coercive field that is only one-third of that of congruent LiNbO3. These properties suggest that zirconium-doped lithium niobate is an excellent choice for nonlinear optical applications.