Enhanced Ultraviolet Damage Resistance in Magnesium Doped Lithium Niobate Crystals through Zirconium Co-Doping.

Tengfei Kong,Yi Luo,Weiwei Wang,Zhiqin Fan,Hongde Liu,Hanxiao Kong

doi:10.3390/ma14041017

Abstract

MgO-doped LiNbO3 (LN:Mg) is famous for its high resistance to optical damage, but this phenomenon only occurs in visible and infrared regions, and its photorefraction is not decreased but enhanced in ultraviolet region. Here we investigated a series of ZrO2 co-doped LN:Mg (LN:Mg,Zr) regarding their ultraviolet photorefractive properties. The optical damage resistance experiment indicated that the resistance against ultraviolet damage of LN:Mg was significantly enhanced with increased ZrO2 doping concentration. Moreover, first-principles calculations manifested that the enhancement of ultraviolet damage resistance for LN:Mg,Zr was mainly determined by both the increased band gap and the reduced ultraviolet photorefractive center O2−/−. So, LN:Mg,Zr crystals would become an excellent candidate for ultraviolet nonlinear optical material.

Highlights

In order to further characterize the optical damage resistance at 355 nm quantitatively, we used the two-wave coupling holographic recording method [21], namely, two coherent e-polarized beams with irradiation intensities of 400 mW/cm2 were focused into the y-oriented plates at the intersecting angle of 28◦ (2θ) to measure the light-induced refractive index changes (∆n) of these crystals
It is found that ZrO2 co‐doping greatly improves the ultraviolet damage resistance considered as the reduction of UV photorefractive centers such as O2−/− near ZrNb of LN:Mg
It knows by the calculated DOS that the charge density of O-2p of LN:Mg is reduced sistance against UV damage of LN:Mg by co‐doping ZrO2 is caused by both the increased dramatically by ZrO2 co-doping, which signifies that the UV photorefractive center O2−/−

Summary

Introduction

Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations. Lithium niobate (LiNbO3 , LN), known as the silicon of nonlinear optics, is famous for its excellent physical properties such as acousto-optic, electro-optic, pyro-electric, piezoelectric, and nonlinear properties [1,2]. It has been grown for more than half a century, LiNbO3 has remained one of the hot issues for researchers up to now [3].

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