周期极化近化学计量掺镁铌酸锂晶体倍频研究

Periodically poled second harmonic green light generation in near-stoichiometric MgO-doped LiNbO3 crystal

摘要: 采用气相输运平衡技术,对不同掺镁浓度的铌酸锂进行了近化学计量处理,并检验了其抗光折变性能。实验结果表明,掺摩尔分数为2%的镁的近化学计量铌酸锂晶体,光折变阈值比同成分晶体提高了4个量级。通过施加4.5kV/mm的脉冲电场,在上述1.0mm厚z切晶体上制备出了周期为6.8μm的均匀畴结构。采用声光调Q Nd:YAG激光器作抽运光源,基频光波波长为1.064μm,平均输入功率为230mW,在室温条件下,得到波长为0.532μm,输出功率为2.8mW的倍频绿光输出,倍频转换效率为1.22%。。

Abstract: LiNbO3 crystal with different MgO doped concentration were processed by vapor transport equilibration.The processed crystals doped 2%(mole fraction) MgO increased the photoreactive damage resistance by at least 4 orders of magnitude compared with congruent crystal.By applying an external electric field of 4.5kV/mm,we obtained a periodically poled domain structure with a 6.8μm period and 1.0mm thickness in the doped MgO2%(mole fraction) near-stoichioment LiNbO3 crystal.A Q-switched Nd:YAG laser was used as the fundamental beam source at 1.064μm.When input power was 230mW,the green SHG at 0.532μm was obtained with 1.22% conversion efficiency.