高Verdet常数的Tb~(3+)铝硼硅酸盐玻璃

本文研究了一种铝硼硅酸盐基质玻璃,通过加大单位体积的稀土离子浓度,并选择P值大的顺磁性Tb~(3+)作为弗尔德常数贡献的主要离子,经反复试验研究,制定合理的熔制工艺,得到性能稳定的透明顺磁旋光玻璃。弗尔德常数V=-0.375/Oe·cm。是目前世界上弗尔德常数较高的磁旋光玻璃。     

采用Ag+离子与TiF6光学玻璃内的K+或Na+离子交换产生高折射率梯度剖面分布

本文介绍了TiF₆光学玻璃的制作。研究了这种玻璃内的K⁺或Na⁺离子与Ag⁺离子交换。使用双光束干涉法观测了干涉纹、并用电子探针扫描电镜测量了Ag⁺、K⁺和Na⁺离子的浓度分布,还着重研究了离子交换后的玻璃裂纹和着色问题。最后,对结果作了讨论。     

高性能大口径顺磁旋光玻璃

旋光玻璃广泛用于激光的调制、偏转、开关和高功率激光系统的隔离器.旋光玻璃的主要性质为费尔德常数.含高顺磁离子的旋光玻璃具有大的费尔德常数,可见区高透过等优点.具有较大磁矩和较低f-d跃迁能隙的顺磁离子铽应具有大的费尔德常数.本工作以高Tb2O3含量的Tb2 O3-B2O3-Al2O3-SiO2为基本系统.研究玻璃的形成;测定了不同Tb3+离子浓度时的费尔德常数,符合线性关系;调整玻璃组成以避免析晶,发展了波长632 nm的费尔德常数为75.1～116.4 rad/(T·m)的TG20,TG28,TG32旋光玻璃系列.建立了10升规模铂坩埚高温熔炉,成形和退火设备.形成口径30 cm旋光玻璃的生产能力.产品的1054 nm光吸收小于0.008 cm-1,1 ns的激光破坏阈值大于8 J/cm2,透过波前畸变小于五分之一波长.所制造的旋光玻璃已用于美国Lawrence Livermore国家实验室,中国"神光Ⅱ"升级,英国Rutherford实验室的Vulcan Laser System和CNRS CEA Luli等高功率激光系统.     

Er3+/Yb3+共掺TeO2-Li2O-B2O3-GeO2玻璃系统的光谱性质和热稳定性研究

制备了Er³⁺/Yb³⁺共掺的70TeO₂-5Li₂O-(25-x)B₂O₃-xGeO₂（x=0,5,10,15,20 mol%）系列玻璃, 研究了玻璃的热稳定性能, 测试了玻璃的吸收光谱、荧光光谱以及Er3+离子4I13/2能级荧光寿命, 并根据McCumber理论计算了Er³⁺离子4I13/2→4I15/2跃迁的受激发射截面. 结果表明：随着GeO₂含量的增加, 玻璃的热稳定性逐渐提高, 荧光谱线半高宽（FWHM）保持在70 nm左右, 而荧光强度和Er3+离子4I13/2能级荧光寿命逐渐提高, 研究表明这种玻璃系统是一种具有应用潜能的宽带光纤放大器用的基质材料.     

第I种非对称三态叠加多模叠加态光场的高次和压缩——第一正交分量的N次方H压缩效应

构造了第孙中禹种强度不等的非对称三态叠加多模叠加态光场|ψ₁^(ABC)〉_q.利用多模压缩态理论研究了态|ψ₁^(ABC)〉_q第一正交分量高次和压缩.结果发现:①当构成态|ψ₁^(ABC)〉_q的三个多模相干态光场的强度不相等时,在一定条件下,态|ψ₁^(ABC)〉_q的第一正交分量可出现任意幂次的高次和压缩.②当上述的三个多模相干态光场强度相等时,态|ψ₁^(ABC)〉_q的第一正交分量的高次和压缩现象消失.在这种情况下,态|ψ₁^(ABC)〉_q的第一正交分量恒处于NH最小测不准态.     

叠加激发双模压缩真空态的量子统计特性(英文)

从激发双模压缩真空态a^+mb^+m|ξ>出发构造了叠加态|Ψ>,研究了|Ψ>的量子统计特性.结果表明:在一定的条件下,随着相位差的变化,叠加态|Ψ>的平均光子数出现类似于Rabi振荡的崩塌与复原现象,而且与单个激发双模压缩真空态a^+mb^+m|ξ>相比,在叠加态|Ψ>中光场的相位压缩和亚泊松光子统计特性都得到了加强.     

两不同奇相干态组成的第种四态叠加多模叠加态光场的等阶N次方Y压缩

根据量子力学中的线性叠加原理,构造了由多模奇相干态与多模复共轭奇相干态这两种不同的奇相干态的线性叠加所组成的第Ⅰ种四态叠加多模叠加态光场|Ψ_o⁽⁴⁾,I〉_q,利用多模压缩态理论,研究了态|Ψ_o⁽⁴⁾,I〉_q的等阶N次方Y压缩特性.结果发现:1)当压缩阶数N为偶数时,在不同的条件下,态|Ψ_o⁽⁴⁾,I〉_q可分别呈现三种状态:a)态|Ψ_o⁽⁴⁾,I〉_q可处于等阶N-Y最小测不准态;b)态|Ψ(4)o,I〉q的第一正交分量可呈现等阶N次方Y压缩效应;c)态|Ψ_o⁽⁴⁾,I〉_q可呈现“半相干态”效应.2)当压缩阶数为奇数时,若果r₁=r₂=r,则在不同的条件下,态|Ψ_o⁽⁴⁾,I〉_q可分别呈现三种状态:a)态|Ψ_o⁽⁴⁾,I〉_q可处于等阶N-Y最小测不准态;b)态|Ψ_o⁽⁴⁾,I〉_q的第一正交分量可呈现等阶N次方Y压缩效应;c)态|Ψ_o⁽⁴⁾,I〉_q的第二正交分量可呈现等阶N次方Y压缩效应.3)“半相干态”是指在一定条件下,态|Ψ_o⁽⁴⁾,I〉_q的两个正交分量其中一个正交分量处于等阶N-Y最小测不准态,另一个正交分量既不处于等阶N-Y最小测不准态也不呈现等阶N次方Y压缩效应.     

Yb3+、Er3+掺杂ZBLAN非晶的激发态频率上转换

我们以前对非晶ZBLAN光纤玻璃中掺杂稀土离子Er³⁺的转换发光的研究表明,在室温、大功率半导体激光器的激发下,Er³⁺的荧光主要是通过单离子步进双光子过程发生的,而其多光子过程虽然非常微弱,但在强的半导体激光的照射下也可产生.通过Yb³⁺的掺杂敏化,Er³⁺的各条荧光谱线都有不同程度的增强,而且增强幅度极大,产生了迄今为止我们所知的最强的绿光发射,Er离子的蓝、紫外的发光也得到子测量.这说明Yb³⁺对Er³⁺的上转换荧光过程有着强烈的敏化作用,这一现象的应用前景有待进一步开拓.     

掺铒碲钨酸盐玻璃光谱性质的研究

合成了不同浓度Er³⁺掺杂的TeO₂-WO₃-Li₂O体系玻璃（TW glasses）,详细研究了掺杂浓度对这种碲钨酸盐玻璃光学特性的影响。计算了Judd Ofelt(J-O)强度参数,研究了掺杂浓度对15 μm发射带宽的影响,及不同掺杂浓度下Er³⁺的⁴I_11/2-⁴I_13/2和⁴I_13/2-⁴I_15/2无辐射跃迁过程。实验得到了在TW 玻璃中Er³⁺的⁴I_13/2-⁴I_15/2跃迁的浓度猝灭速率约为跃迁的浓度猝灭速率约为0.8×10^-18cm³·s^-1,这对寻求Er³⁺在碲钨酸盐玻璃中的合理掺杂浓度有一定的参考意义,这对寻求Er³⁺在碲钨酸盐玻璃中的合理掺杂浓度有一定的参考意义。实验发现Er³⁺的⁴I_11/2-⁴I_13/2无辐射弛豫速率在这种玻璃体系中约是不含WO₃的碲酸盐玻璃中的2倍,说明含WO₃的掺铒碲钨酸盐玻璃更有利于在980 nm激光泵浦下实现15 μm光放大。     

二价Ba2+、Pb2+和四价Ti4+在硼硅酸盐玻璃系统中对Li+/Na+离子交换的影响

本文讨论了在硼硅酸盐玻璃系统中引入二价Ba²⁺、Pb²⁺和四价Ti⁴⁺后,由于Pb²⁺和Ti⁴⁺配位结构的变化,引起Pb²⁺、Ti⁴⁺场强及其与O^2-离子间距的变化,对Li⁺/Na⁺离子交换产生影响,从而改变折射率差值(ΔN)和折射率分布.     

Solid-state NMR study of bioactive binary borosilicate glasses

A series of binary borosilicate glasses prepared by the sol-gel method are shown to be bioactive. Tetraethyl orthosilicate (TEOS) and trimethylborate (TMB) in acidic medium are used to prepare xB₂O₃·(1−x)SiO₂ glass systems for x=0.045-0.167. The formation of a layer of apatite-like mineral on the glass surface becomes apparent after soaking in simulated body fluid for 48 h. We have measured the ¹¹B-¹¹B homonuclear second moments of the borosilicate glasses and inferred that no macroscopic phase separation occurred in our glasses. The ¹¹B chemical shift data also show that the formation of clustered boroxol rings is negligible in our glass system. Although the bioactivity of our borosilicate glasses is less than that of CaO-SiO₂ sol-gel glasses, these simple binary systems could be taken as reference glass systems for the search of new bioactive borosilicate glasses.     

Low-temperature absorption centers in some simple glasses

At the temperature of liquid nitrogen, glasses were irradiated with Co⁶⁰ radiation and the induced absorption spectra were measured. A strong increase in the 640 nm band was observed in sodium silicate and unleached sodium borosilicate glasses; a new band at 820 nm appeared in potassium silicate glass; and the intensity of the band at 240 nm increased in sodium borate glass and in unleached sodium borosilicate glasses.In conclusion, the authors express their gratitude to N. Z. Andreeva for her assistance in the measurements.     

钕离子掺杂和钕铝共掺高硅氧玻璃的光谱性质研究

基于多孔玻璃烧结的方法制备了钕离子掺杂和钕铝共掺高硅氧玻璃，测量了掺钕高硅氧玻璃的吸收光谱、荧光光谱和荧光寿命. 利用Judd-Ofelt理论计算得到了钕离子在高硅氧玻璃中的强度参数，计算并对比了掺钕高硅氧玻璃和钕铝共掺高硅氧玻璃的理论荧光寿命、受激发射截面和发光量子效率.讨论了钕铝共掺高硅氧玻璃中铝离子的掺入对玻璃发光性质的影响. 通过与其他掺钕氧化物玻璃和一些商用硅酸盐玻璃的主要光谱性质的比较，掺钕高硅氧玻璃显示了较好的光谱性质，有可能成为一种应用于高能和高频激光领域的新型激光材料. 关键词： 掺钕高硅氧玻璃 钕铝共掺 光谱性质 Judd-Ofelt理论     

Evidence for formation of Se molecular clusters during precipitation of CdSe<Subscript>1−<Emphasis Type="Italic">x</Emphasis></Subscript>S<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript> nanoparticles in glass

While studying the effect of thermal treatment at 625–700°C on the formation of borosilicate glass-embedded CdSe or CdSe_1−x S _x nanocrystals, pronounced bands at 323 and 646 cm⁻¹ were observed in the Raman spectra. They are assigned to Se₂ clusters on the base of their frequency positions, widths, intensities, and resonance behavior. The precipitation of Se₂ molecular clusters in borosilicate glass is shown to occur when the heat treatment temperature and/or duration are beyond the range, most suitable for the formation of CdSe or CdSe-rich CdSe_1−x S _x nanocrystals.     

Raman analysis of perrhenate and pertechnetate in alkali salts and borosilicate glasses

Sodium borosilicate glasses containing rhenium or technetium were fabricated and their vibrational spectra studied using confocal Raman microscopy. Glass spectra were interpreted relative to new high‐resolution spectra of pure crystalline NaReO₄, KReO₄, NaTcO₄, and KTcO₄ salts. Spectra of perrhenate and pertechnetate glasses exhibited sharp Raman bands, characteristic of crystalline salt species, superimposed on spectral features of the borosilicate matrix. At low concentrations of added KReO₄ or KTcO_4, the characteristic pertechnetate and perrhenate features are weak, whereas at high additions, sharp peaks from crystal field‐splitting and C_4h symmetry dominate glass spectra, clearly indicating ReO₄⁻ or TcO₄⁻ is locally coordinated with K and/or Na. Peaks indicative of both K and Na salts are evident in many Raman spectra, with the Na form being favored at high concentrations of the source chemicals, where more K⁺ is available for ion exchange with Na⁺ from the base glass. The observed ion exchange likely occurred within depolymerized channels where nonbridging oxygens create segregation from the glass network in regions containing anions such as ReO₄⁻ and TcO₄⁻ as well as excess alkali cations. Although this anion exchange provides evidence of chemical mixing in the glass, it does not prove the added salts were homogeneously incorporated in the glass. The susceptibility to ion exchange from the base glass indicates that long‐term immobilization of Tc in borosilicate glass must account for excess charge compensating alkali cations in melt glass formulations. Published 2014. This article is a U. S. Government work and is in the public domain in the USA.     

An effective compliant substrate for low-dislocation relaxed Si1-xGex growth

An effective compliant substrate for Si_1-xGe_x growth is presented. A silicon-on-insulator substrate was implanted with B and O forming 20 wt % borosilicate glass within the SiO₂. The addition of the borosilicate glass to the buried oxide acted to reduce the viscosity at the growth temperature of Si_1-xGe_x, promoting the in situ elastic deformation of the thin Si (∼20 nm) layer on the insulator. The sharing of the misfit between the Si and the Si_1-xGe_x layers was observed and quantified by double-axis X-ray diffraction. In addition, the material quality was assessed using cross-sectional transmission electron microscopy, photoluminescence and etch pit density measurements. No misfit dislocations were observed in the partially relaxed 150-nm Si_0.75Ge_0.25 sample as-grown on a 20% borosilicate glass substrate. The threading dislocation density was estimated at 2×10⁴ cm^-2 for 500-nm Si_0.75Ge_0.25 grown on the 20% borosilicate glass substrate. This method may be used to prepare compliant substrates for the growth of low-dislocation relaxed SiGe layers. Received: 4 January 2001 / Accepted: 30 May 2001 / Published online: 17 October 2001     

A glass thinning and texturing method for light incoupling in thin‐film polycrystalline silicon solar cells application

For polycrystalline silicon (poly‐Si) thin‐film solar cells on ～3 mm borosilicate glass, glass thinning reduces the glass absorption and light leaking to neighbouring cells; the glass texturing of the sun‐facing side suppresses reflection. In this Letter, a labour‐free wet etching method is developed to texture and thin the glass at the same time in contrast to conventionally separated labour‐intensive glass thinning and texturing processes. For 2 cm² size poly‐Si thin‐film solar cells on glass superstrate, this wet etching successfully thins down the glass from 3 mm to 0.5 mm to check the ultimate benefit of the process and introduces a large micron texture on the sun‐facing glass surface. The process enhances J_sc by 6.3% on average, with the optimal J_sc enhancement of 8%, better than the value of 4.6% found in the literature. This process also reduces the loss in external quantum efficiency (EQE loss), which is due to light leaking to neighbouring cells, dramatically. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

NMR Insights into Wasteforms for the Vitrification of High-Level Nuclear Waste

Magic-angle spinning nuclear magnetic resonance of ¹¹B, ²⁹Si and ²⁷Al has been used to study the distribution of nonbridging oxygen atoms (NBO) in an alkali borosilicate glass to which surrogate oxides for high-level radioactive waste have been added. The properties of such glasses are shown to depend on the fraction N ₄ of four-coordinated boron atoms (B4) and on the fraction of silicate tetrahedra possessing one NBO, Q³. The aqueous corrosion rate increases with Q³ content, as does weight loss due to evaporation from the melt. The activation energy for direct current conduction scales with N ₄. Values of N ₄ obtained for these glasses deviate from those predicted by the currently accepted model and are strongly affected by the modifier or intermediate nature of the surrogate oxide and also by its effect on the distribution of NBO between the silicate and borate polyhedra. Authors' address: Diane Holland, Department of Physics, University of Warwick, Coventry CV4 7AL, UK     

Study of Volume Electric Charge in Radioactive Dielectrics by the Method of “Acoustic Sounding”

The formation of the volume electric charge in dielectrics containing radioactive β-isotope has been theoretically proposed. A method of calculating the value of the charge for both uniform and nonuniform distribution of the isotope in the volume is described. The method of the “acoustic sounding” has been used for the experimental study of charge distribution in the sample of crystalline Y₃Al₅O₁₂ (⁹⁰Y) and borosilicate glass (⁹⁰Sr + ⁹⁰Y). The results obtained are in good accord with the theoretical evaluations. A conclusion has been drawn to the effect that the measurement of volume charge distribution can be used to study the absorption of β-radiation in a substance and spatial distribution of β-isotope in the material.