Study On Properties Of Zr:Yb:Nd:LiNbO₃ Crystals With Different[Li]/[Nb]ratio

In this paper,a series of Zr:Yb:Nd:LiNbO₃ crystals doped with different[Li]/[Nb]were prepared by Czochralski.And the appropriate growth process and growth conditions were determined.The optical damage resistance,defect structure and optical properties of the crystal were tested.Increasing the[Li]/[Nb]of the Zr:Yb:Nd:LiNbO₃ crystal is of great significance for practical use of the crystal.It was found by inductively coupled plasma atomic emission spectrometry that as the[Li]/[Nb]increases,the intrinsic defect inversion Nb(Nb_Li^4（10）)and lithium vacancy(V^-_Li)concentration in the crystal decreases and the concentration increases of Yb³⁺and Nd³⁺ions are in the crystal.Infrared spectroscopy,birefringencegradient method,ultraviolet-visible-near-infraredabsorption spectroscopy and X-ray diffraction method were used to analyze the doping occupancy of doped ions and the inherent defect structure of the crystal.The results show that Zr:Yb:Nd:LiNbO₃ crystals decrease with the increase of[Li]/[Nb],and the internal defects of the crystal decrease,the ultraviolet absorption edge first produces purple shift,and the red shift,Zr⁴⁺,Yb³⁺and Nd³⁺ions are substituted for the lithium and niobium sites doped into the crystal and the optical uniformity becomes better.The photodamage performance of Zr:Yb:Nd:LiNbO₃ crystal was studied by light scattering threshold energy flow method.The increase of[Li]/[Nb]and the crystal of Zr:Yb:Nd:LiNbO₃ were obtained from the experimental results.The resistance to photodamage is directly proportional.After[Li]/[Nb]reaches 1.38,the resistance to photodamage of Zr:Yb:Nd:LiNbO₃ is increased by two orders of magnitude compared with[Li]/[Nb]=0.946.The exposure energy of ZrYbNd_1.38 is235.03 J/cm²,and the exposure energy of ZrYbNd_0.946 is 5.79 J/cm²,which is 43times.