Optical properties of Mg2＋, Yb 3＋, and Ho3＋ tri-doped LiNbO3 crystals

A series of LiNbO_3 crystals tri-doped with Mg~（2＋）,Yb~（3＋）,and Ho~（3＋） are grown by the conventional Czochraski technique.The concentrations of Mg~（2＋）,Yb~（3＋）,and Ho~（3＋） ions in Mg：Yb：Ho：LiNbO_3 crystals are measured by using an inductively coupled plasma atomic emission spectrometry.The x-ray diffraction is proposed to determine the lattice constant and analyze the internal structure of the crystal.The light-induced scattering of Mg：Yb：Ho：LiNbO_3 crystal is quantitatively described via the threshold effect of incident exposure energy flux.The exposure energy（E_r） is calculated to discuss the optical damage resistance ability.The exposure energy of Mg（7 mol）：Yb：Ho：LiNbO3 crystal is 709.17 J/cm~2,approximately 425 times higher than that of the Mg（l mol）：Yb：Ho：LiNbO_3 crystal in magnitude.The blue,red,and very intense green bands of Mg：Yb：Ho：LiNbO_3 crystal are observed under the 980-nm laser excitation to evaluate the up-conversion emission properties.The dependence of the emission intensity on pumping power indicates that the up-conversion emission is a two-photon process.The up-conversion emission mechanism is discussed in detail.This study indicates that Mg：Yb：Ho：LiNbO_3 crystal can be applied to the fabrication of new multifunctional photoluminescence devices.