Fe^(3+)对KDP晶体生长影响的研究

金属离子对KDP晶体的影响是多方面的。本文采用不同的过饱和度,在不同的Fe3+掺杂浓度的生长溶液中生长KDP晶体,定量地研究了Fe3+对KDP晶体生长的影响。实验发现,无论是在高过饱和度还是在低过饱和度下生长KDP晶体,在一定的浓度范围内,Fe3+的掺入既可以增加生长溶液的稳定性,又可以有效抑制晶体柱面的扩展,而且晶体基本不楔化,同时,对晶体光学性能的影响也不大。

Yb^(3+):YVO_4晶体的生长及光谱性能研究

采用提拉法生长出光学质量优良的Yb3 + :YVO4晶体 ,研究生长过程中工艺参数的控制。测得掺杂浓度为18.1%Yb3 + :YVO4晶体中Yb3 + 离子的有效分凝系数Keff为 0 96。测定了不同Yb3 + 离子掺杂浓度晶体的吸收光谱和荧光光谱 ,并分别计算了不同掺杂浓度下Yb3 + :YVO4晶体的光谱参数。本文总结和解释了掺杂浓度影响其性能的规律 ,讨论了Yb3 + :YVO4晶体作为激光晶体的优点。

溶液掺杂法制备掺了Tm^(3+)单模石英光纤

本文主要论述了溶液掺杂法制备掺Ｔｍ^（３＋）单模石英光纤的技术和工艺、Ｔｍ^（３＋）掺杂浓度、脱水过程与Ｔｍ^（３＋）沿光纤芯部剖面掺杂分布的控制，以及光纤诸参数的优化设计。

溶液掺杂法制备掺Tm^(3+)单模石英光纤

主要论述了溶液掺杂法制备掺Ｔｍ ３＋ 单模石英光纤的技术和工艺：Ｔｍ３＋ 掺杂浓度、脱水过程、Ｔｍ ３＋ 沿光纤芯部剖面掺杂分布的控制。

Effect of dopant concentration on the spectra characteristic in Zr^(4+) doped Yb:Nd:LiNbO_3 crystals

A series of Yb：Nd：LiNbO3 crystals tridoped with various concentrations of Zr4＋（1 mol.%, 2 mol.% and 4 mol.%） were grown by the Czochralski technique from the congruent melt. The X-ray powder diffraction, UV-Vis-NIR absorption spectra and IR transmittance spectra were measured to analyze the crystal composition and defect structure. The Zr4＋, Yb3＋ and Nd3＋ ions in LiNbO3 crystal had two effects： volume compensation effect and ion valence state compensation effect. The Zr O2 doping threshold concentration was nearly 2.0 mol.%. The fluorescence emissions of Nd3＋ ions and Yb3＋ ions were observed under 808 nm excitation. The intensity of fluorescence emissions enhanced with the increasing of the Zr4＋ doping concentrations. The Zr：Yb：Nd：LiNbO3 crystals with 4 mol.% doping concentration of Zr4＋ ion revealed strong emission around 1 μm, which is of great significance for laser materials.

Impact of grain size,Pr3+ concentration and host composition on non-contact temperature sensing abilities of polyphosphate nano- and microcrystals

In this article,varied praseodymium polyphosphate hosts:MI(Li,Na K)Pr(PO3)4 microcrystals and LiLa1-xPrx(PO3)4(x = 0.01 ^-1)nanocrystals were successfully synthesized by the flux method and the coprecipitation technique,respectively.The size of stoichiometric nanocrystals of LiPr(PO3)4 was tuned by the te mpe rature of thermal treatment in range of 35-145 nm.In order to dete rmine the most suitable material for the non-contact optical thermometric applications,the temperature sensing measurements were carried out by using luminescence intensity ratio(LIR)of emission bands corresponding to the ^3 P1→ ^3H5 and ^3P0→ ^3 H5 electronic transitions of Pr3+ ions into the 123-423 K temperature range.The influence of the host material composition of MⅠ(Li,Na,K)Pr(PO3)4 microcrystals on the sensitivity of luminescent thermometers was studied.It is found that the sensitivity of lithium praseodymium polyphosphate is the highest of all micropowders under investigation.Moreover,it is found that the nanocrystals reveal much higher relative sensitivity in respect to the microcrystalline counterparts.The highest sensitivity of LIR temperature sensing is found for LiPr(PO3)4 nanocrystals(35 nm grain size)in the whole temperature range,reaching 0.283%/K at 164 K.The impact of the average grain size on the sensitivity of LIR based thermometers of LiPr(PO3)4 nanocrystals was investigated.It is found that the reduction of the grain size from 145 to 35 nm results in the enhancement of the relative sensitivity from0.156 to 0.240%/K at 223 K.Additionally it is found that the high dopant concentration possesses favorable influence on the relative sensitivity of LiLa1-xPrx(PO3)4 nanocrystalline luminescent thermometers.

镱铒共掺硅酸盐玻璃三波段光致发光特性数值分析

考虑两级合作上转换、激发态吸收、交叉弛豫等非线性效应,建立了镱铒共掺硅酸盐玻璃材料9个能级的11个速率方程。唯象地构造了合作上转换系数随镱铒掺杂浓度的变化函数,数值模拟了镱铒共掺硅酸盐玻璃1530,664,549 nm 3个波段的光致发光强度与掺杂浓度、抽运功率的变化关系。计算结果表明:掺铒浓度一定,镱浓度增加时,对于1530 nm荧光而言,有最佳的掺镱浓度,但红光和绿光荧光强度随掺镱浓度始终增强;保持镱铒掺杂浓度不变,抽运功率增加时,3种荧光强度均单调增强,差别在于增幅速率不同,且近红外光强有饱和趋势。计算结果与实验测量相吻合。