掺钕聚甲基丙烯酸甲酯的光谱性质

研究了三价钕离子在钕螯合物掺杂的聚甲基丙烯酸甲酯(PMMA)中的吸收光谱和发射光谱.根据Judd-Ofelt理论,从吸收光谱计算了钕离子在PMMA中的光学跃迁的强度参量Ω2、Ω4和Ω6(Ω2=28.99×10-20 cm2,Ω4=5.29×10-20 cm2,Ω8=3.82×10-20 cm2).用强度参量计算了钕离子激发态(4F3/2)的辐射跃迁几率(2221.54 s-1)和辐射寿命(450.14μs),同时计算了4F3/2 →4IJ'跃迁的受激发射截面σij和荧光分支比β.分析表明,Nd(DBM)3Phen掺杂的PMMA可望用于激光放大器件.     

掺铒氟化物玻璃ZBLALip光谱性质和Judd-Ofelt理论分析

测量了常温下,Er3+离子在氟化物玻璃ZBLALip中的吸收光谱和荧光寿命;应用Judd-Ofelt理论计算了Er3+离子的谱线强度、自发辐射几率A、荧光分支比β和辐射寿命τrad等光谱参量,并拟合了相应的强度参数Ωt=2,4,6),分别为(Ω2=2.80×10-20cm2,Ω4=0.95×10-20 cm2,Ω6=0.94×10-20 cm2;利用McCumber理论计算了能级4I13/2→4I15/2跃迁的受激发射截面Οem;通过计算发现,该材料的量子效率较高,达到90%,可成为新的激光材料,为拉制高Q值的光学介质微球腔提供了参考.     

ZnWO4晶体中Ho3+离子光谱参数计算

Ho3 ∶ZnWO4是一种潜在的优良激光晶体,对其光谱性能的研究具有一定价值。采用引上法生长出光学质量的Ho3 ∶ZnWO4单晶,测定了晶体的吸收光谱和发射光谱,利用乍得-奥菲而特(Judd-Ofelt)理论计算出Ho3 离子在ZnWO4晶体中的强度参数Ω2=3.757×10-20cm2,Ω4=2.089×10-20cm2,Ω6=4.659×10-20cm2。由此得到5I7→5I8跃迁的辐射寿命和发射截面积分别为17.08 ms,0.667×10-18cm2;四能级跃迁系统5S2→5I7的发射截面积为1.200×10-18cm2,荧光分支比为0.3525。从而提出5I7→5I8,5S2→5I7可作为产生激光的跃迁通道进行激光实验。     

GGG:Ho~(3 )晶体的光谱强度参数

本文应用Judd-Ofelt理论,由晶体的吸收光谱获得了Gd_3Ga_5O_(12):Ho~(3 )(简写GGG:Ho~(3 )振子强度的实验与计算值,用最小二乘方法拟合出的强度参数为Ω_2=0.24×10~(-20)cm~2、Ω_4=1.41×10~(-20)cm~2、Ω_6=1.09×10~(-20)cm~2。进而计算了电偶跃迁几率与辐射寿命。     

利用窄得-奥菲特理论研究Tm:Lu2SiO5晶体的光谱特性

采用丘克拉斯基(Czochralski)技术生长了掺铥硅酸镥(Tm∶Lu2SiO5,Tm∶LSO)晶体;测量了LSO晶体在室温下的非偏振吸收光谱和非偏振荧光光谱;利用窄得-奥菲特(Judd-Ofelt)理论计算了Tm∶LSO晶体的窄得-奥菲特强度参数、振子强度、自发辐射概率、辐射寿命、积分吸收截面和积分发射截面.Tm∶LSO晶体的强度参数为Ω2=9.1355×10-20cm2,Ω4=8.4103×10-20cm2,Ω6=1.5908×10-20cm2;Tm∶LSO晶体在1.9μm附近有明显的发射峰(3F4→3H6跃迁),相应的辐射寿命为2.03 ms,积分发射截面为5.81×10-18cm2,半峰全宽(FWHM)为250 nm.用Tm∶LSO晶体在77 K温度下实现了激光运转.利用792 nm的激光二极管(LD)作为抽运源,获得中心波长为1960 nm的激光输出,抽运阈值为2.13 kW/cm2.     

Tm∶YAP激光晶体光谱参数的计算

采用丘克劳斯基(Czochralski)法生长了Tm∶YAP晶体,研究了该晶体在室温下的吸收光谱和荧光光谱。结果表明,Tm∶YAP晶体在689.5 nm和795 nm左右有较强的吸收峰,分别对应于3H6→3F3和3H6→3H4的能级跃迁,半峰全宽(FWHM)分别为22.5 nm和30 nm,吸收截面分别为1.89×10-20cm2和1.35×10-20cm2。荧光光谱表明Tm∶YAP晶体发射波长为1.89μm,相应的荧光寿命为13.90 ms,发射截面为1.58×10-19cm2。根据乍得-奥菲特(Judd-Ofelt)理论计算了Tm3 在Tm∶YAP晶体中的强度参数:Ω2=1.4560×10-20cm2,Ω4=2.0673×10-20cm2,Ω6=0.3181×10-20cm2。结果表明,Tm∶YAP晶体具有宽的吸收峰、长荧光寿命和较大的积分发射截面的性质,非常适合于激光二极管(LD)抽运,有利于获得低阈值高效率的2μm波段激光输出。     

Tm:YAP激光晶体光谱参数的计算

采用丘克劳斯基(Czochralski)法生长了Tm:YAP晶体,研究了该晶体在室温下的吸收光谱和荧光光谱.结果表明,Tm:YAP晶体在689.5 nm和795 nm左右有较强的吸收峰,分别对应于3H6→3F3和3H6→3H4的能级跃迁,半峰全宽(FWHM)分别为22.5 nm和30 nm,吸收截面分别为1.89×10-20 cm2和1.35×10-20 cm2.荧光光谱表明Tm:YAP晶体发射波长为1.89μm,相应的荧光寿命为13.90 ms,发射截面为1.58×10-19 cm2.根据乍得-奥菲特(Judd-Ofelt)理论计算了Tm3+在Tm:YAP晶体中的强度参数:Ω2=1.4560×10-20cm2,Ω4=2.0673×10-20 cm2,Ω6=0.3181×10-20 cm2.结果表明,Tm:YAP晶体具有宽的吸收峰、长荧光寿命和较大的积分发射截面的性质,非常适合于激光二极管(LD)抽运,有利于获得低阈值高效率的2μm波段激光输出.     

Tm3+掺杂GeO2-AlF3-Na2O玻璃的制备与光谱特性

用高温熔融法制备了Tm2O3掺杂深度分别为1、2、3、4和5 wt%的82GeO2-8AlF3-10Na2O(摩尔比)的玻璃.从吸收光谱特性出发,应用Judd-Ofelt(J-O)理论,计算得到了Tm3+的J-O强度参数(Ω2,Ω4,Ω6)及Tm3+各激发态能级的自发跃迁几率、荧光分支比以及辐射寿命等光谱参量.在808...     

掺铒TeO2-B2O3-Nb2O5-ZnO玻璃系统的光谱性质和热稳定性的研究

制备了碲酸盐玻璃样品70TeO2-(15-x)B2O3-xNb2O5-15ZnO-1wt%Er2O3(TBN,x=0,3,6,9,12,15 mol%).测试了玻璃样品的热稳定性和光谱性质.根据Judd-Ofelt理论计算了TBN玻璃中Er3 离子的强度参数(Ω2=(5.42～6.76)×10-20 cm2,Ω4=(1.37～1.73)×10-20cm2,Ω6=(0.70～0.94)×10-20 cm2),发现随着Nb2O5含量的增加,Ωt(t=2,4,6)先增加后减小.研究表明Er-O键共价性主要受基质玻璃中非桥氧数的影响,而阴阳离子间电负性的影响可以忽略.应用McCumber理论计算了Er3 离子的受激发射截面(σe=(0.77～0.91)×10-20 cm2)和Er3 离子4I13/2→4I15/2发射谱的半高宽度(FWHM=65～73 nm).比较了不同基质玻璃中Er3 离子的荧光半高宽和受激发射截面.结果表明TBN玻璃系统具有较好的带宽性能,是一种制备宽带光纤放大器的潜在基质材料.     

Nd:CaNb2O6晶体的生长及光谱性质

采用提拉法沿c向成功生长出质量优良的Nd:CaNb2O6新型单晶.测量了晶体的室温吸收光谱,在808 nm处吸收截面为5.04×10-20cm2,吸收带宽为8 nm.根据Judd-Ofelt理论,拟合出晶体场强度参数Ωt(t=2,4,6):Ω2=5.321×10-20cm2,Ω4=1.734×10-20cm2,Ω6=2.889×10-20cm2.荧光辐射寿命τrad为167.02μs,计算的荧光分支比β为:β1=36.03%,β2=52.29%,β3=11.15%,β4=0.533%.这些良好的光谱性质表明Nd:CaNb2O6晶体将成为固态激光器中有潜力的激光增益介质.     

Resolution Enhancement Technology:Integrated Process Solutions using OPC

DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.     

Cost-effective test solutions for smart card and other integrated flash applications

From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.     

Theoretical analysis of the relationship between the Brillouin gain coefficient and the strain in the optical-fiber sensors

The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.     

An improved parallel thinning algorithm with two subiterations

The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.     

Novel fiber-optical interferometer with miniaturized probe for in-hole measurements

Today, micro-system technology and the development of new MEMS （Micro-Electro-Mechanical Systems） are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.     

Study of waveguide coupling efficiency in hybrid silicon lasers

This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel＇s.     

Teleportation of an arbitrary unknown N-qubit entangled state under the controlling of M controllers

A new quantum protocol to teleport an arbitrary unknown N-qubit entangled state from a sender to a fixed receiver under M controllers(M < N) is proposed. The quantum resources required are M non-maximally entangled Greenberger-Home-Zeilinger (GHZ) state and N-M non-maximally entangled Einstein-Podolsky-Rosen (EPR) pairs. The sender performs N generalized Bell-state measurements on the 2N particles. Controllers take M single-particle measurement along x-axis, and the receiver needs to introduce one auxiliary two-level particle to extract quantum information probabilistically with the fidelity unit if controllers cooperate with it.     

Diode-end-pumped Nd:YVO4/LBO lasers with 4.2W continuous-wave output at 457 nm

A continuous-wave (CW) 457 nm blue laser operating at the power of 4.2 W is demonstrated by using a fiber coupled laser diode module pumped Nd: YVO4 and using LBO as the intra-cavity SHG crystal With the optimization of laser cavity and crystal parameters, the laser operates at a very high efficiency. When the pumping power is about 31 W, the output at 457nm reaches 4.2 W, and the optical to optical conversion efficiency is about 13.5% accordingly. The stability of the out putpower is better than 1.2% for 8 h continuously working.     

Call for Papers

正Wireless Body-area Networks The last decade has witnessed the convergence of three giant worlds:electronics,computer science and telecommunications.The next decade should follow this convergence in most of our activities with the generalization of sensor networks.In particular with the progress in medicine,people live longer and the aging of population will push the development of wireless personal networks     

Call for Papers—Feature Topic,Vol.12,No.7,2015

正Information Centric Networking Information-Centric Networking(ICN) is an emerging direction in Future Internet architecture research,gaining significant tractions among academia and industry.Aiming to replace the conventional host-to-host communication model by a data-centric model,ICN treats data content as the first