不同掺杂镁含量的镁镝铌酸锂晶体光学性能研究

发布时间：2018-01-31 14:47

本文关键词： 镁镝铌酸锂晶体缺陷结构紫外-可见-近红外吸收光谱 J-O理论抗光损伤性能　出处：《哈尔滨理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：本文采用提拉法生长了一系列Mg~(2+)离子浓度分别为0、4、5和6 mol%的Mg:Dy:LiNbO_3晶体。对于掺杂不同Mg~(2+)离子浓度后,Mg:Dy:LiNbO_3晶体内的缺陷结构、紫外-可见-近红外吸收光谱以及晶体抗光损伤能力强弱的影响进行了研究。本论文采用电感耦合等离子发射光谱法(ICP-AES)测试Mg~(2+)离子和Dy~(3+)离子进入LiNbO_3晶体中的实际含量,分析Mg~(2+)离子掺杂浓度对晶体中Mg~(2+)离子和Dy~(3+)离子的实际含量的影响。经测试发现,对于掺杂不同浓度Mg~(2+)离子的晶体中,Mg~(2+)离子和Dy~(3+)离子的占位是有差异的。当掺杂Mg~(2+)离子的浓度还未达到其阈值浓度时,Mg~(2+)离子将会以替换4LiNb(10)形成LiMg(10)缺陷结构的形式进入晶体中。而当掺杂Mg~(2+)离子的浓度接近或高于阈值浓度时,4LiNb(10)缺陷结构将会全部被替换,此时Mg~(2+)离子进入晶体后,为了达到电荷平衡,将占据正常晶格的Li位和Nb位,从而分别形成LiMg(10)和3NbMg-缺陷结构。通过原子力显微镜(AFM)来测试Mg:Dy:LiNbO_3晶体的表面形貌。实验结果表明,Mg(4mol%):Dy:LiNbO_3晶体表面粗糙度的均方根(rms)为14.758 nm,表明Mg:Dy:LiNbO_3晶体的表面形貌是光滑的。根据紫外-可见-近红外吸收光谱的测试结果,本实验中利用J-O理论,分别计算了不同Mg~(2+)离子浓度Mg:Dy:LiNbO_3晶体的J-O强度参数。结果表明Mg(6mol%):Dy:LiNbO_3晶体的J-O理论强度参数分别为Ω_2=7.53×10~(-20) cm~2,Ω_4=6.98×10~(-20) cm~2和Ω_6=3.09×10~(-20) cm~2。获得Mg(6mol%):Dy:LiNbO_3晶体的光谱质量因子(X=2.26)要比本文中其他样品以及已报道其他Dy掺杂晶体高。本实验选择光散射曝光能量流阈值法对Mg:Dy:LiNbO_3晶体的抗光损伤性能进行研究与分析,结论为Mg~(2+)的掺杂浓度越高,Mg:Dy:LiNbO_3晶体的抗光损伤能力越强。当Mg~(2+)离子掺杂浓度达到了6mol%,其曝光能量为709.27 J/cm~2,是未掺杂Mg~(2+)离子的Mg-0样品的320倍。实验结果表明,在本研究中所生长的一系列Mg:Dy:LiNbO_3晶体的表面光滑且没有明显的开裂,其中Mg(6mol%):Dy:LiNbO_3晶体具有较好的光学性能与抗光损伤能力。
[Abstract]:A series of Mg~(2 ions were grown by Czochralski method. 5 and 6 mol% Mg:Dy:LiNbO_3 crystals. For the doped Mg~(2) ions, the defect structure in mg: Dy-: Linbo _ 3 crystal is obtained. The effects of UV-Vis / NIR absorption spectra and the ability of crystal to resist light damage were studied. In this thesis, Mg~(2 was measured by inductively coupled plasma emission spectrometry (ICP-AES). The actual content of ions and Dy~(3 ions entering LiNbO_3 crystals. The effect of doping concentration of Mg~(2) ion on the content of Mg~(2 ion and Dy~(3 ion in crystal was analyzed. For crystals doped with different concentrations of Mg~(2 ions. When the concentration of doped Mg~(2) ions has not reached its threshold concentration. Mg~(2) ions will enter the crystal in the form of replacing 4LiNb10) to form LiMg10) defect structure, and when doped with Mg~(2). When the concentration of ions is close to or higher than the threshold concentration. When the Mg~(2 ions enter the crystal, in order to achieve charge equilibrium, they will occupy the Li and NB sites of the normal lattice. LiMg10) and 3NbMg- defect structures were formed respectively. The surface morphology of Mg:Dy:LiNbO_3 crystals was measured by atomic force microscopy (AFM). The RMS of the surface roughness of Mg(4mol%):Dy:LiNbO_3 crystal is 14.758 nm. It is shown that the surface morphology of Mg:Dy:LiNbO_3 crystal is smooth. According to the results of UV-Vis near infrared absorption spectra, J-O theory is used in this experiment. The J-O intensity parameters of Mg:Dy:LiNbO_3 crystal with different Mg~(2 concentration were calculated respectively. The results show that the J-O intensity parameter of Mg:Dy:LiNbO_3 crystal with different Mg~(2 ion concentration is 6mol). The J-O theoretical strength parameters of Dy1: Linbo _ 3 crystal are 惟 _ 2 ~ (3) 脳 10 ~ (3) ~ (-20) cm~2, respectively. \\\ {\}\\\ {\}\\\ {\}\\\ {\}\\\. Spectral quality Factor X _ (2.26) of Dy10: Linbo _ 3 Crystal. It is higher than other samples and other Dy doped crystals reported in this paper. In this experiment, we selected the light scattering exposure energy flow threshold method for mg: Dy. The light damage resistance of LiNbO_3 crystal was studied and analyzed. Conclusion the higher the doping concentration of Mg~(2 is, the stronger the light damage resistance of mg: Dyw Linbo _ 3 crystal is. When the doping concentration of Mg~(2) reaches 6 mol%. The exposure energy is 709.27 J / cm ~ (2), which is 320 times higher than that of the Mg-0 sample without doping Mg~(2 ion. The surface of a series of Mg:Dy:LiNbO_3 crystals grown in this study is smooth without obvious cracking. Among them, Mg(6mol%):Dy:LiNbO_3 crystal has good optical properties and light damage resistance.
【学位授予单位】：哈尔滨理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O734

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