Li(Sc,M)Si_(2)O_(6)∶Cr^(3+)(M=Ga^(3+)/Lu^(3+)/Y^(3+)/Gd^(3+))的近红外发光性能

荧光转换型近红外发光二极管(NIR pc-LED)具有体积小、谱带宽、峰位易调谐等优点,是新一代NIR光源发展的前沿,其关键在于研发可被蓝光有效激发的高效率宽带近红外荧光粉。LiScSi_(2)O_(6)∶Cr^(3+)荧光材料的激发波长为460 nm,发射峰位在845 nm,光谱带宽为156 nm,内量子效率为64.4%。基于该体系,本文通过M离子(M=Ga^(3+),Lu^(3+),Y^(3+),Gd^(3+))取代Sc^(3+)的方式对其性能进行调控。结果表明,引入M离子易生成杂相或发生相变,降低了材料的发光性能。本文从晶体结构出发对其调控过程进行了分析。

Cr^(3+)∶LiCaAlF_6晶体生长和激光特性

首次报道熔体提拉法生长Ｃｒ∶ＬｉＣＡＦ（Ｃｒ３＋∶ＬｉＣａＡｌＦ６）晶体的生长工艺，研制出质量较好的晶体尺寸达２０～２５×９０～１２０ｍｍ。测定了晶体对８０９ｎｍ红外波段的吸收系数μ为１０－２量级，晶体中无ＯＨ－。Ｃｒ∶ＬｉＣＡＦ可调谐灯泵激光器获得的宽带能量输出１．６Ｊ，阈值５０．５Ｊ，调谐范围为７３０～８４８ｎｍ，用ＫＤＰ调Ｑ，单脉冲宽度４８ｎｓ，峰值功率达１．３×１０６Ｗ。

Cr：LiCaAlF_6晶体的缺陷研究

本文报道了用化学腐蚀、光学显微镜、扫描电子显微镜、Ｘ射线能谱分析等方法观测布里奇曼法生长的Ｃｒ：ＬｉＣａＡｌＦ＿６（简称Ｃｒ：ＬｉＣＡＦ）晶体中的缺陷。分析讨论了晶体中缺陷的形成原因和减少缺陷的措施。

Investigation of the high-temperature Cr：LiSrAlF6 crystal by Raman spectroscopy

In this paper, Cr-doped LiSrAlF6 crystals are investigated using high-temperature Raman spectroscopy and the single-crystal Raman spectra of Cr：LiSrAlF6 are analysed by factor group theory and comparison with other fluorides. The results indicate that Cr：LiSrAlF6 is stable below its melting point; Raman peaks located at 561,322 and 250 cm-1 are assigned to the Alg modes of AlF6, SrF6 and LiF6 octachdra, respectively; with temperature increasing, Raman peaks associated with AlF6 octahedra shift towards low frequencies, while LiF6 and SrF6 octahedra are temperature- insensitive; around the crystal melting point, three new Raman peaks occur, which are associated with the AlF6 octahedral chain structure. Finally, the microstruetural evolution of Cr：LiSrAlF6 from room temperature to its melting point is discussed based on its Raman spectra.

Cr∶LiSAF可调谐激光晶体的生长及应用

本文报道了高质量Cr∶LiSrAlF6 (简称Cr∶LiSAF)晶体的软坩埚下降法生长及其激光特性。采用“固相反应”氟化法处理原料 ,能有效的去除原料中的氧化物成分和水 ,得到可用于晶体生长的纯净原料 ;用厚度仅为 0 .0 6～ 0 .0 9mm的铂金软坩埚 ,温度梯度控制在 2 0℃ /cm以下 ,用低速率的坩埚下降法生长出尺寸达2 0× 130mm的优质单晶 ,能实现 1mol%～ 15mol%各种浓度的均匀掺杂。在闪光灯泵浦的条件下 ,该晶体脉冲激光输出能量为 3.4 5J ,晶体的储能密度达到 2 .4 6J/cm3,激光斜效率高达 5.85% ,点效率为 3.32 %。用 4 88nm的单线氩离子泵浦Cr∶LiSAF晶体 ,获得了脉冲宽度 4 0fs、平均输出功率 4 5mW的稳定自锁模脉冲序列。

Cr^(3+)∶LiSrAlF_6的晶体生长及其激光性能研究

采用坩埚下降法生长了Ｃｒ３＋∶ＬｉＳｒＡｌＦ６（Ｃｒ∶ＬｉＳＡＦ）晶体。以功率为９００ｍＷ，波长为４８８ｎｍ的单线氩离子激光泵浦６ｍｏｌ％的Ｃｒ∶ＬｉＳＡＦ晶体，实现了Ｃｒ∶ＬｉＳＡＦ激光器的飞秒级自锁模运转，得到了脉冲宽度为４０ｆｓ，重复频率为１００ＭＨｚ，平均输出功率为４５ｍＷ的稳定的锁模脉冲序列。用闪光灯泵浦１ｍｏｌ％的Ｃｒ∶ＬｉＳＡＦ激光棒，在输入能量为１２０Ｊ时，得到了１２７０ｍＪ的激光输出，斜效率达２．２７％。

含有三羰基铬结构单元的杂双核二丁基锡羧酸酯的合成及其晶体结构

利用二丁基氧化锡与Cr(CO)3(η6-C6H5CO2H)反应制得新型杂双核二聚有机锡羧酸酯化合物——{[Cr(CO)3(η6-PhCO2)Sn(nBu)2]2O}2(1),其结构经NMR,IR和X-射线单晶衍射表征。1属单斜晶系,P21/c空间群,晶胞参数a=1.4234(4)nm,b=1.613 3(4)nm,c=1.9071(5)nm,β=110.334(5)°,V=4.1065(19)nm3,Z=4,Dc=1.611Mg.m-3,μ=1.771mm-1,F(000)=1992,R=0.0685,Rw=0.1385。

二极管抽运的Cr^(3+):LiSrAlF_(6)激光器的研究

论述了一全固化 Cr3+:L i Sr Al F6激光实验装置 ,用连续二极管激光器对 1mm晶体薄片纵向抽运 ,在平行平面腔结构中 ,产生 5.2 m W的激光输出 .自由振荡光谱范围为 832～ 84 5nm,斜率效率为 15% .

灯泵浦Cr^(3+):LiCaAlF晶体可调谐Q开关激光器

报道了闪光灯泵浦掺铬氟化铝钙锂（ＣｒＬｉＣＡＦ）可调谐、Ｑ开关激光器的实验结果。调谐范围为７３０～８５０ｎｍ，峰值波长为７８０ｎｍ。激光最大输出能量为１．６２Ｊ，斜率效率为０．８％，阈值为５０．４Ｊ。ＫＤ＊Ｐ晶体电光调Ｑ，单脉冲半宽度为４８ｎｓ，峰值功率为１．３×１０６Ｗ。

Measurement of refractive indices and thermal refractive index coefficients of Cr^3+ Be3Al2Si6O18 by auto-collimation method

The principal refractive indices and the thermal refractive index coefficients for Be3Al2Si6O18 crystal doped with 1.01wt% Cr2O3 have been accurately measured by the auto-collimation method at wavelengths of 0.488, 0.53975, 1.064, 1.0795 and 1.3414 mm, and temperatures of 308.2, 328.6, 359.1 and 395.4 K respectively. Based on the measured results of principal indices of 0.488, 0.6328, 1.0795 and 1.3414靘, the Sellmeier抯 equations and the thermal refractive index coefficients have been obtained, and the result has been proven to be accurate by error analysis.