RbTiOAsO4(RTA)晶体的电光性能

测量了ＲｂＴｉＯＡｓＯ４（ＲＴＡ）晶体的电光系数、介电常数和交流电导率,结果为：电光系数γ１３＝１０．８,γ２３＝１７．３,γ３３＝４０．０,γ５１＝１２．３,γ４２＝１４．６ｐｍ／Ｖ;介电常数ε１１＝ε２２＝１２,ε３３＝２１;交流电导率σｃ＝３．６×１０－８ｓ／ｃｍ。结果表明ＲＴＡ晶体波导调制器的品质因子ｎ７γ２／ε比ＫＴＰ晶体高１５％,但是其交流电导率比ＫＴＰ晶体小了两个数量级。这些性能使ＲＴＡ晶体有希望应用于波导调制器和其它电光器件。     

ZnCd(SCN)4晶体的电学性能和电光性能

测量了 Zn Cd(SCN) 4晶体的介电常数和直流电导率 ,结果为 :介电常数 εa=6 .9,εc=7.4。直流电导率ρa=4 .6× 10 1 0 Ω· cm,ρc=1.4× 10 1 1 Ω· cm。并用干涉法测量了该晶体的全部压电应变常数和电光系数 ,其结果为 :压电应变常数 d31 =1.5 p C/N,d36 =9.5 p C/N ,d1 4=1.6 p C/N,d1 5=15 .3p C/N;电光系数γ1 3=0 .0 4 pm /V ,γ6 3=9.4 pm /V,γ4 1 =1.3pm /V ,γ51 =1.7pm/V。     

低对称晶体CdCa4O（BO3）3电光系数的测量

用干涉法测量了低对称晶体GdCa4O(BO3)3的全部电光系数。为了分离测量交叉电光系数γ51,γ53,γ42和γ62,采用了新的样品趋向。测量结果为：γ11＝0．4pm/V,γ21＝0．5pm／V,γ31＝0．6pm／V,γ13＝0．1pm／V,γ23＝0．4pm/V,γ33＝2．0pm／V,γ51＝0．7pm／V,γ42＝0．5pm／V,γ62＝0．8pm／V。     

RbTiOAsO4晶体的电学性能

测量了ＲｂＴｉＯＡｓＯ４晶体的电阻率,介电常数,热释电系数和压电应变系数。     

NaY（WO4）2：Tm,Yb晶体的上转换发光

用高频加热Czochralski法生长了Yb^3 ,Tm^3 共掺的NaY(WO4)2晶体,测量了晶体在室温下的290－2000nm内的吸收谱,并对跃迁的能级进行了指认。在972nm二级管激光器泵浦下观察到Tm^3 的793nm和457nm上转换发光,研究了NYW晶体中Yb^3 向Tm^3 进行的能量传递的机制。     

Electro-optic effect in proton exchanged LiNbO3 andLiTaO3 waveguides

Electro-optic properties of proton-exchanged (PE) waveguide layers in LiTaO₃ and LiNbO₃ are studied and related to their optical characteristics. The proton-exchange process induces a degradation of the electro-optic activity in both types of waveguides, PE LiNbO₃ and PE LiTaO₃. The measured electro-optic effect is close to the detection sensitivity even when the exchange regime is performed at low temperatures for short periods of time. The PE samples have been annealed (APE waveguides) and the changes of their r₃₃ electro-optic coefficient has been followed at successively higher temperatures and periods of time. Subjected to annealing at temperatures between 265-420°C, the LiTaO₃ layers show a partially recovered r₃₃ coefficient, the recovering being different for quick and slow cooling of the samples. In thin APE LiNbO₃ waveguiding layers a restoration of r₃₃ up to 75% of the bulk value is observed due to the annealing at temperatures between 200-340°C     

激光二极管抽运Nd∶YVO4/YVO4复合晶体激光器

在高功率激光二极管(LD)抽运的情况下,对比分析了Nd∶YVO4/YVO4复合晶体和Nd∶YVO4单一晶体的激光特性。实验证明,复合晶体能够有效地降低晶体内的温度梯度,减小由端面变形带来的热透镜效应,获得比单一晶体高出许多的输出功率。采用Z型折叠腔,研究了Nd∶YVO4/YVO4复合晶体KTP倍频特性,当抽运功率为17W时,获得了6.23W的绿光输出,抽运光到绿光的转换效率高达37%。     

Spectroscopic Properties and Laser Performance of Er3+ and Yb3+ Co-Doped GdAl3(BO3)4 Crystal

An Er:Yb:GdAl₃(BO₃)₄ crystal was grown and room-temperature polarized absorption, emission, and gain spectra were investigated. Fluorescence decay curves of Er³⁺ at 1530 nm and Yb³⁺ at 1040 nm in the crystal were measured. Efficient laser operation of Er:Yb:GdAl₃(BO₃)₄ crystal at 1.5-1.6 mum was realized. Quasi-continuous-wave output powers of 1.8 W with slope efficiency of 19% and 0.78 W with slope efficiency of 14% were achieved in diode-pumped c-cut and c-cut and a-cut crystals, respectively. The output spectrum and polarization of Er:Yb:GdAl₃(BO₃)₄ laser were also investigated.     

二磷酸钾镨晶体的生长

用助熔剂缓冷法从KCl-KF熔体中生长出K_3Pr(PO_4)_2晶体。实验给出了助熔剂挥发量对晶体产率的影响。化学组成分析和X射线分析证明,所得的晶体是K_3Pr(PO_4)_2。测定了晶体的红外光谱、紫外可见吸收光谱和荧光光谱。     

发光晶体Na_5Er（WO_4）_4的光谱性质和Er~（3＋）的光谱参数计算

制备了Ｎａ５Ｅｒ（ＷＯ４）４的粉末和单晶，测定了晶格参数、单晶吸收光谱，激发和发光光谱。计算了吸收谱线振子强度，根据Ｊｕｄｄ－Ｏｆｅｌｔ理论拟合出Ｅｒ３＋发光光谱的三个强度参数Ω２，４，６＝１．７４，１．４６，０．５１×１０－２ｃｍ２，计算了自发辐射电偶和磁偶跃迁振子强度和跃迁几率、辐射寿命、荧光分支比和积分发射截面等光谱参数，讨论了Ｅｒ３＋发光谱线出激光的可能性。     

Na_5Sm(WO_4)_4发光晶体的生长及光谱特性

本文报道了用助熔剂缓冷法生长新型发光晶体Na_6Sm(WO_4)_4,计算了它的晶格常数,测定了它的红外光谱、吸收光谱、荧光光谱和激发光谱,并确定了晶体中Sm~(3+)离子的能级.研究表明,该晶体是有前途的激光晶体.     

Eu2+掺杂Sr5(PO4)2SiO4磷灰石荧光粉的发光性能研究

采用高温固相法制备了Sr5－x (PO₄)₂SiO₄:xEu²⁺(x =0.010,0.015,0.020,0.025,0.050, 0.100)荧光粉,研究掺杂 浓度和测试温度对荧光粉发光性能的影响。随着Eu²⁺掺杂浓度的增加,发射强度呈现 先增大后减小的变化 趋势,并在x=0.015时达到最大值。Eu 2+掺杂浓度较低时(x≤0.025),Eu²⁺取代不同格位的 Sr²⁺,使得发射 光谱具有双发射峰;当x＞0.025时,由于 存在Eu 1到Eu 2的能量传递使发射光谱中Eu 1的峰位消失,只存 在Eu 2的峰位。发射光谱随Eu²⁺浓度增大出现了红移现象,这是由于半径较小的Eu 2+(0.109nm)取代较 大的Sr²⁺(0.113nm)使得晶胞收缩,晶场强度增大,从而导 致Eu²⁺的5d能级劈裂程度增大,电子跃迁释 放能量降低。此外,测试温度增加时,发射光谱出现与Varshini方程不相符的蓝移现象,这 是晶格结构稳定性和声子辅助隧穿效应共同作用使较小波长的Eu 1的发射居于主导地位的结 果。     

钼酸盐Na5TbxEu1—x（MoO4）4的发射光谱研究

测定了室温下Ｎａ５ＴｂｘＥｕ１－ｘ（ＭｏＯ４）４的发射光谱。发现随ｘ的增加，Ｔｂ＾３＋离子５４６ｎｍ（＾５Ｄ４→＾７Ｆ５）的荧光发射亦随这增加。同时观察到，当ｘ＞０．７时，发光相对强度变化会出现突变。     

Diode-pumped ytterbium-doped Sr5(PO4)3F laser performance

The performance of the first diode-pumped Yb³⁺-doped Sr ₅(PO₄)₃F (Yb:S-FAP) solid-state laser is discussed. An InGaAs diode array has been fabricated that has suitable specifications for pumping a 3×3×30 mm Yb:S-FAP rod. The saturation fluence for diode pumping was deduced to be 5.5 J/cm ² for the particular 2.8 kW peak power diode array utilized in our studies. This is 2.5× higher than the intrinsic 2.2 J/cm ² saturation fluence as is attributed to the 6.5 nm bandwidth of our diode pump array. The small signal gain is consistent with the previously measured emission cross section of 6.0×10^-20 cm², obtained from a narrowband-laser pumped gain experiment. Up to 1.7 J/cm³ of stored energy density was achieved in a 6×6×44 mm Yb:S-FAP amplifier rod. In a free running configuration, diode-pumped slope efficiencies up to 43% (laser output energy/absorbed pump energy) were observed with output energies up to ~0.5 J per 1 ms pulse. When the rod was mounted in a copper block for cooling, 13 W of average power was produced with power supply limited operation at 70 Hz with 500 μs pulses     

硼酸铝钕[NdAl_3(BO_3)_4](NAB)的脉冲激光特性

本文报道了我所生长的大尺寸硼酸铝钕晶体的脉冲激光特性。当用氙闪光灯泵浦时,φ3.2mm×23.7mm的NAB激光棒,最大激光输出为每个脉冲422mJ。对于φ1.8mm×2.4mm的激光棒,激光阈值为67mJ。激光输出为线性偏振光,波长1.063μm。用BDN染料片调Q时,φ1.2mm×8.4mm的NAB棒激光单脉冲宽度为8ns,光束发散度为2mrad。     

Er_xY_(1-x)Al_3(BO_3)_4晶体的生长及性质

研究了助熔剂法合成Er_xY_(1-x)Al_3(BO_3)_4(EYAB)晶体的工艺;对该体系的物相进行了差热和X-射线分析,确定了K_2Mo_3O_(12)及EYAB相的生成温度得到不同组成的EYAB晶体;观察了晶体缺陷,测定了晶体学参数及热稳定性。     

Al2(WO4)3的激光烧结合成及特性

采用激光烧结技术快速成功地将比例适当的Al2O3和WO3粉末合成了形貌良好且致密的Al2(WO4)3材料,并对该材料采用多种分析手段进行了分析。 拉曼光谱分析说明在合适工艺参数下激光烧结可避免原料挥发，使原料完全参与反应。X射线衍射(XRD)分析表明合成物主要是Al2(WO4)3，属空间群Pnca，具有正交结构，可能显示负热膨胀特性，另外还含有少量的AlxWO3(x≤1)和WO3-x(x<1)。扫描电镜(SEM)发现合成物晶粒呈球形、细小、排列致密、少有气孔、尺寸约在10 nm左右。能量散射光谱(EDS)分析显示合成物内部成分分布均匀。热分析则得出合成物中少许杂相为复杂非平衡相。     

激光晶体K_3Nd(PO_4)_2的生长及其光谱

用助熔剂法从KF-KCl熔体中生长出了K_3Nd(PO_4)_2和K_3Nd_xLa_(1_x)(PO_4)_2晶体。化学组成分析和X射线衍射分析证明,所得到的晶体是K_3Nd(PO_4)_2。测定了它们的红外光谱、吸收光谱、荧光光谱和荧光寿命。     

Review of a New IR Nonlinear Optical BaGa4Se7 Crystal

A newly grown BaGa4Se7 crystal has been synthesized via the Bridgman-Stockbarger technique. This new crystal has advantages of high nonlinear optics (NLO) coefficients, high laser damage thresholds, and wide transparent regions. The BaGa4Se7 crystal has bright application prospects as a nonlinear gain medium in mid-infrared and terahertz regions. In this paper, the crystalline structure and synthetic method of the BaGa4Se7 crystal are introduced. The refractive indices and absorption coefficients along three dielectric axes between 0.1 THz and 1.0 THz are also obtained. The terahertz difference frequency generation (THz-DFG) characteristics based on the BaGa4Se7 crystal in the frequency range of 0.1 THz to 1.0 THz are analyzed theoretically and the phase-matching conditions are calculated. The application of BaGa4Se7 crystals in terahertz wave generation is also discussed.     

Fluorescence analysis of chromium-doped forsterite(Mg2SiO4)

The polarized absorption spectra, emission spectra, and fluorescence dynamics of Cr:forsterite are presented and analyzed in detail. At least three different kinds of emitting centers are identified by time-resolved spectroscopy. These correspond to two sorts of octahedrally coordinated Cr³⁺ ions and one Cr⁴⁺ with various possible environments. The infrared laser active center is identified with the latter species, and its infrared absorption and emission properties are attributed to excited state-ground state optical transitions without any thermalization process into the excited state