Rational Design of a LiNbO3-like Nonlinear Optical Crystal, Li2ZrTeO6, with High Laser-Damage Threshold and Wide Mid-IR Transparency Window.

With existing and emerging technologies urgently demanding the expansion of the laser wavelengths, high-performance nonlinear optical (NLO) crystals are becoming indispensable. Here, a prospective NLO crystal, Li2ZrTeO6, is rationally designed by the element substitution of Nb for Zr and Te from LiNbO3, which has been recognized as one of the most commercial NLO crystals. Li2ZrTeO6 with R3 symmetry inherits the structural merits of LiNbO3 (space group R3 c) and thus meets the requirements for NLO applications, including noncentrosymmetric crystal structure, moderate birefringence, and phase-matchability. Moreover, it can be exploited to achieve more outstanding optical damage resistant behavior (>1.3 GW cm-2), exceeding 22 times that of LiNbO3, which is more suitable for high-energy laser applications. Notably, this compound displays the widest IR absorption edge (7.4 μm) among all of the noncentrosymmetric tellurates reported so far. These excellent attributes suggest that Li2ZrTeO6 is a promising candidate for providing high NLO performance. The substitution of Nb for Zr and Te from LiNbO3 demonstrates a viable strategy toward the rational design of NLO crystals with anticipated properties.