Spectral Parameters of Nd^3＋ Ion in Nd^3＋：KLu（WO4）2 Crystal

1 INTRODUCTION There has been increasing interest in the re-search of diode laser-pumped solid-state lasers in re-cent years because of the rapid development of highpower diode lasers. Nd:YAG and Nd:YVO crystalsare commercially available, but limited to low Nd3 (= 1 at.%) doping concentration and to narrow ab-sorption bands near the diode emission wavelengthof 808 nm. Therefore, it is necessary to explore moreefficient crystal materials for diode-pumped solid-state lasers. The alkali …     

Structure of GdMg（BO2）5 Crystal

1 INTRODUCTION With the development of diode-pumped solid-sta- te lasers, the research to find more efficient materials for these lasers is gaining more importance. The luminescent materials host LnMgB5O10 may become potential solid-state laser materials[1, 2]. Nd3 -doped GdMg(BO2)5 as a potential diode-pumped laser crystal has been grown in our lab and characterized by a very strong absorption at near 808 nm and intense emission. Although the previous work repor- ted LaMg(BO2)5 with…     

Structure of Non-stoichiometric Sr6Gd0.61Sc1.39（BO3）6 Crystal

1 INTRODUCTION With the increasing interest in diode-pumped solid state lasers, researches on more efficient new materials for diode pumping become more important. The double borates are a type of excellent laser gain media, for example, Nd3 -doped RAl…     

Growth and Spectral Properties of Nd^3＋ Doped KLa（MoO4）2 Crystal

1 INTRODUCTION There has been an increasing interest in the re- search of diode-pumped solid-state lasers in recent years because of the rapid development of high power diode lasers. The absorption peak of Nd3 ions at about 800 nm corresponding to 4I9/2→ 2H9/2 tran- sition is suitable for commercial laser diode GaAlAs pumping[1]. KLa(MoO4)2 is a kind of disordered crystalline host for lasing rare-earth ions[2], and it belongs to Scheelite (CaWO4) structure[3]. The disorder derives…     

Spectral Parameters of Nd^3＋ Ion in Nd^3＋：NaGd（MoO4）2 Crystal

1 INTRODUCTION Since the diode-laser pumped solid-state lasers were found in a wide variety of applications in the fields of military, industry, medical treatment and scientific researches due to the advantages of high stability, compactness, high efficiency and long life- time, the research on more efficient new materials with improved spectral properties for diode pumping has become more important. Molybdate crystals with general formula M’Re(MoO4)2 (M’ = Li, Na, K) have been repor…     

Growth and Characteristics of Nd^3＋：GdAl3（BO3）4 Crystal

Nd^3 :GdAl3(BO3)4(NGAB) crystal with the size of 30 mm was grown from the solvent system of K2O-Gd2O3-MoO3-B2O3 by combining accelerated seed rotation technology with medium seeded solution growth (MSSG) method,and its crystal structure has been determined by X-ray powder diffraction.It crystallizes in the trigonal system,space group R32 with a=9.2743(2),c=7.2438(1)A,V=538A^3,Z=3and Dc=4.379g/cm^3,The absorption and emission spectra of NGAB in the function of σ and π polarizations at room temperature have been measured.UV generation tuneable in 378-382nm,green(531nm) generation and blue generation tuneable in 436-443 nm as well as red(669)nm generation by self-frequency changing were obtained with the oupput of 105, 119.5,445and 19μJ/pulse,respectively,when the crystal was pumped by a dye laser.     

A Novel Coumarin-based Fluorescence Chemosensor for Fe^3＋

A novel coumarin derivative[7-diethylamino-2-oxo-2H-chromene-3-carboxylic acid（6-amino-pyridin2-yl）-amide,CFe1] has been synthesized and its potential application as a chemosensor for the detection of metal ions has been further investigated.The responses of CFe1 to Fe^3＋ were studied by fluorescence emission spectrometry in the presence of other metal ions such as Al^3＋,Ba^2＋,Ca^2＋,Co^3＋,Cr^3＋,Cu^2＋,Fe^2＋,Hg^2＋,Mg^2＋,Mn^2＋,Na^＋,Ni^＋,Pb^2＋,Zn^2＋,K^＋,and Ag^＋.CFe1 showed a good selectivity for Fe^3＋ with fast response,a wide pH span of 3.3-9.18,and a large Stocks shift.CFe1 in the presence of Fe^3＋ and ethylene diamine tetraacetic acid（EDTA） makes the blue solution fade to colorless,which is due to the formation of CFe1-Fe^3＋ complex instead of any catalytic action of Fe^3＋.Furthermore,the imaging of Fe^3＋ in cultured single mice microglia cells was realized with the aid of CFe1,indicating that CFe1 has a great potential to be used as promising models for the future design of novel and robust chemosensor for metal ion detection in the field of biomedical and environmental analyses.     

Study on fire-retardant nanocrystalline Mg-Al layered double hydroxides synthesized by microwave-crystallization method

Since the layered double hydroxides (abbreviatedas LDHs), known as anionic clays or like-hydrotalciteswere firstly reported to be used as precursors of newcatalytic materials by S. Miyata[1] in 1971, theirpreparations, ion-exchanges with the balancing inter-layer anions, structure characteristics and the otherpotential applications have attracted more and moreinterests. The preparation of such materials could beperformed by various methods such as the coprecipita-tion[2], the heat-crystalliza…     

Hydrothermal Synthesis and Structure Characterization of Diamine-templated Two-dimenisional Cerium Sulfate,[C_6N_2H_(14)][Ce(SO_4)_2(H_2O)_2]·0·5SO_4·2·5H_2O

Open-framework materials are of great interestfrom both the theoretical and practical points of viewdue to their catalytic, absorbent, and ion-exchangeproperties[1]. In the past decade, the study of structur-ally and chemically diverse open framework solids hasbeen flourishing[2—7]. A large variety of silicates[2],phosphates[3]and carboxylates[4]with open-frameworkstructures have been synthesized with organic amines astemplates. Ithas also been demonstrated thatother oxy-salts such as selenat…     

SYNTHESIS OF SOLUBLE POLY(3-HEXYL-2,5-THIENYLENE VINYLENE) FROM THIOPHENE

INTRODUCTIONConjugated polymers have attracted more and more attention since the discovery of highly conductivepolyacetylene[1-3]. Their possible applications in sensors, and electroluminescene devices[4-5] etc. have alsostimulated the synthesis of new conjugated polymers. Because of the presence of π-conjugated bonds in thebackbone, they have band structures (such as the energy level of HOMO and LUMO, bandgap etc.) similar tothose of inorganic semiconductors such as silicon; conjugat…     

掺钕聚甲基丙烯酸甲酯的光学特性

Nd(DBM)3Phen-doped (DBM is dibenzoylmethane and Phen is phenanthroline) polymethyl methacrylate (PMMA) is prepared. Optical absorption, excitation and emission spectra were analyzed for Nd3+ in Nd(DBM)3Phen-doped PMMA. Using the Judd-Ofelt theory, the absorption spectrum was analyzed. The Judd-Ofelt(J-O) intensity parameters of Nd(DBM)3Phen-doped polymethyl methacrylate were calculated to be Ω2 = 20.97 × 10-20 cm2, Ω4 = 3.42 × 10-20 cm2, Ω6 = 2.90 × 10-20 cm2. The radiative lifetime (631 μs)of the excited 4F3/2 level is given. The stimulated emission cross-sections and the fluorescence branch ratios for the 4F3/2 →4 IJ/ transitions are also evaluated. Analysis reveals that Nd(DBM)3Phen-doped PMMA is promising for application in polymer optical fibers and planar waveguides.     

Yb3+敏化宽波带掺Er3+氟磷酸盐玻璃的发光性质及Judd-Ofelt理论研究

采用高温熔融法制备了一种新的Er3+/Yb3+共掺氟磷酸盐玻璃,测试和分析了其密度、吸收光谱以及荧光光谱,讨论了Er3+离子和Yb3+离子对光谱性质的影响.根据Judd-Ofelt理论计算了玻璃中Er3+离子的强度参数Ωt(t=2,4,6),分别为Ω2=4.36×10-20cm2,Ω4=1.35×10-20cm2,Ω6=0.79×10-20cm2,以及Er3+离子4I13/2能级荧光寿命τm=8.26ms.主发射峰1.53μm处半高宽(FWHM)为68nm.根据McCumber理论计算了Er3+的受激发射截面σe=8.5×10-21cm2.比较了不同玻璃基质中Er3+离子的光谱特性,结果表明:Er3+/Yb3+双掺氟磷酸盐玻璃在1.53μm附近具有较宽的半高宽和较大的受激发射截面,是一种高增益掺铒光纤放大器的理想介质材料.     

Optical-transition Probability of Tm^3＋ Ions in Tm^3＋／Er^3＋：YVO4 Crystal

1INTRODUCTIONThelasersoperatedataround2mmwavelengthhavegainedmuchinterestbecauseofvariousappli-cations,e.g.(1)groundorspaceremotesensingforLIDARandmetrology,(2)medicalapplicationssinceliquidwaterhasastrongabsorptionbandnear2mm,and(3)eyesafelaser[1,2].The2…     

Growth and Spectroscopic Properties of Nd3＋：Sr3Gd2（BO3）4 Crystal

<正>This paper reports the growth,X-ray diffraction and spectroscopy of Nd~(3+):Sr_3Gd_2(BO_3)_4 crystal.A Nd~(3+):Sr_3Gd_2(BO_3)_4 crystal with dimensions ofφ20×45 mm~3 has been grown by the Czochralski method.Nd~(3+):Sr_3Gd_2(BO_3)_4 crystal belongs to the orthorhombic system,space group Pnma(D_(2h))with a=0.7401,b=1.604 and c=0.8755 nm.The absorption and emission spectra of Nd~(3+):Sr_3Gd_2(BO_3)_4 were investigated.The absorption cross sectionσ_a is 3.11×10~(-20)cm~2 at 808 nm. The absorption transition at 808 nm has an FWHM of 14 nm.The luminescence lifetimeτ_f is 51.7 us.The emission cross sectionσ_e at 1064 nm wavelength is 1.09×10~(-19)cm~2.     

Growth,Structure,and Spectroscopic Characteristics of the Nd^3＋：LiGd（WO4）2 Crystal

The Nd3+:LiGd(WO4) 2 crystal with dimensions of 25mm×28mm×16mm was grown by the top-seeded solution growth method from the 60 mol% Li2W2O7 flux. LiGd(WO4) 2 crystallizes in the tetragonal system with space group I41/a(C4h6) and cell parameters: a = 5.1986 and c = 11.2652 . The hardness is about 5.0 Mohs' scale. The specific heat is 0.40 J·g-1·K-1 at 50 oC. The thermal expansion coefficients for a-and c-axes are 1.314×10-5 and 2.052×10-5 K-1,respectively. The room-temperature polarized absorption and emission spectra and the fluorescence decay curve was measured. The parameters of oscillator strengths,the spontaneous transition probabilities,the fluorescence branching ratios,the radiative lifetimes,and the emission cross sections have been investigated based on Judd-Ofelt theory and Füchtbauer-Ladenburg method. The absorption cross-section is 5.19×10-20 cm2 at 805 nm for π-polarization and its line width is 15 nm;the emission cross section is 1.726×10-19 cm2 at 1060.5 nm for π-polarization. The fluorescence and radiative lifetimes are 86 and 158 μs,respectively. The fluorescence quantum efficiency is 54.43%.     

Spectral properties of Nd-doped BiB_3O_6 crystal

Transparent Nd : BiB3O6 crystal has been grown by top-seeded method. The refraction indices of the crystal were measured and the parameters of chromatic dispersion were fitted. The room temperature absorption spectra of the crystal have been measured and compared with that of 0.2 mol/L NdCI3 solution. According to Judd-Ofelt (JO) theory, the spectral strength parameters Ω2 = 0.1776×10-20 cm2, Ω4 = 0.1282×10-20 cm2 and Ω6 = 0.1357×10-20 cm2 of Nd3+ ion were fitted. The radiative transition probabilities AJ,(?), oscillator strengths fJ,(?), radiative lifetime T and the branching ratio β(?) have all been calculated. Based on these parameters, the properties and application perspective are discussed.     

Nd:GdVO4晶体的生长与光谱性能

采用Czochralski法生长了均匀透明的Nd:GdVO4晶体,测量了其室温偏振吸收谱,并与0.2mol·L^-1的NdCl3溶液的室温吸收谱进行了比较。根据Judd-Ofelt理论,拟合出晶体场唯象强度参数：Ω2=12.629×10^-20cm^2,Ω4=4.828×10^-20cm^2,Ω6=8.425×10^-20cm^2.计算了各能级的辐射跃迁几率AJ,J',振子强度PJ,J;,辐射寿命τ,荧光分支比βJ'等光学参量。并用LD激光器泵浦Nd:GVO4晶体,当量大泵浦功率为26W时,得到输出功率为14.3W波长为1.06μm的基频光,光-光转换效率为55%,斜效率为63%。