超宽带ASE光纤光源研究

报道了一种简单结构的超宽带ASE光纤光源,采用两个相同的980 nm半导体激光器对同一段掺铒光纤进行抽运,通过选择合适的掺铒光纤长度及调节两个抽运源的抽运功率,获得了带宽大于80 nm、输出功率21 mW的C L波段的ASE荧光输出。     

超宽带ASE光纤光源研究

报道了一种简单结构的超宽带ASE光纤光源，采用两个相同的980nm半导体激光器对同一段掺铒光纤进行抽运，通过选择合适的掺铒光纤长度及调节两个抽运源的抽运功率，获得了带宽大于80nm、输出功率21mW的C L波段的ASE荧光输出。     

新型中心波长稳定的高效率L波段掺铒光纤超荧光光源

采用后向抽运的两级级联的掺铒光纤超荧光光源的新型结构,运用同步抽运技术对两级光纤按比例进行后向抽运,从而实现高效率且中心波长稳定的L波段超荧光光源输出.研究了光纤总长度、两级光纤长度分配以及抽运比例对超荧光光源输出特性参数的影响.结果表明,通过采用两级级联后向结构可以将光谱从C波段有效地转移到L波段,而且能够实现在高抽运功率下具有中心波长对抽运功率波动不敏感的特性.在290 mW功率1:1抽运下,实验获得了输出功率97 mW,线宽47.3 nm,中心波长稳定的L波段超荧光光源.     

一种简单而性能优良的C+L波段掺铒宽带光源

报道了一种结构简单、工作在C L波段的掺铒宽带光源.实验中用3 dB宽带耦合器作为光纤反射镜,同时利用功率控制电路使光源输出光稳定,先用两个980 nm二极管作为抽运源,将后向的C波段ASE重新引回光纤中,提高了抽运源的利用效率和光纤输出光的稳定性,优化掺铒光纤长度,获得了功率高达26.67 mW(14.26 dBm)的C L波段ASE光输出,平均波长1 550.887 nm.之后采用一个二极管实现双抽运得到了同样的结果.     

单级结构C+L波段掺铒光纤宽带光源

报道了利用双向抽运单级掺铒光纤结构研制的高效率C L波段放大自发辐射(ASE)宽带光源。实验表明,该结构在一定的掺铒光纤长度范围内,均可通过调节前后向抽运功率来获得带宽达80 nm(1525~1605 nm)光谱平坦的C L波段宽带光源。光源的抽运转换效率与掺铒光纤长度、前后向抽运功率分配有关。选择所需的最短掺铒光纤长度制作光源,既可以节省光纤,降低成本,还可以提高抽运转换效率。利用该光源结构获得了输出功率为13.5 dBm,抽运转换效率达23.2%的高效率C L波段放大自发辐射宽带光源。     

高功率Er/Yb共掺光纤超荧光光源

为了获得高功率超荧光输出,采用6个976nm的LD,通过一个光纤束耦合器同时抽运Er/Yb共掺光纤,分别研究了单程后向结构和双程后向结构超荧光光源的输出特性.采用单程后向装置,当抽运功率为957mW时,输出功率为120.4mW,斜率效率达到17.5%.在双程后向结构的实验装置中加入4m掺Er光纤,有效地将超荧光的3dB带宽拓展到88nm.     

一种新颖的反射结构高功率超宽带光纤光源

报道了一种新型高功率超宽带光纤光源。利用980nm激光二极管(LD)和1480nmLD双向抽运掺铒光纤，经光纤环镜反射后，得到C L波段自发辐射谱。通过调整980nmLD和1480nmLD的功率，在1524．O～1600．6nm(76．6nm)范围内，自发辐射谱功率高于-18．8dBm，并且在1539．2～l600．6nm(61．4nm)范围内，自发辐射谱的平坦度为2．8dB。总荧光功率为22．1mW。转换效率为18．8％。如果不加环镜，并且保持相同的抽运条件，得到的放大自发辐射(ASE)谱宽在1525～1565nm的C波段范围，其总的荧光功率为7．1mW，转换效率仅为6％。通过分析加环镜情况与不加环镜情况下所得到的自发辐射谱，以及加环镜情况下采用不同的抽运方式得到的自发辐射谱，最终得出结论，通过加环镜，并且用980nmLD和1480nmLD双向抽运，得到了具有最佳效果的超宽带光纤光源。实验过程中通过调整980nmLD和1480nmLD的功率，曾得到28．5mW的荧光功率，转换效率为22．3％。     

基于超宽带铋铒共掺光纤光源的光纤光栅传感

为开发低成本且性能稳定的超宽带光源,研究了基于铋铒共掺光纤(BEDF)的超宽带光源的输出光谱特性。当使用830nm激光器抽运时,输出光谱覆盖了整个O、E、S、C、L波段,半峰全宽达525nm。将该BEDF超宽带光源应用于波分复用光纤光栅传感系统,实现了O波段和C波段的应力传感。实验结果表明,将BEDF超宽带光源应用于大规模光纤光栅传感网络,可大幅度提高传感系统的复用容量。     

高功率高效率掺铒光纤超荧光光源

优化设计了高功率、高效率掺铒光纤超荧光光源的参数。采用商用掺铒光纤,针对双程后向结构,首先仿真了光源输出功率和带宽随掺铒光纤长度的变化,并用对等实验验证了模拟结果,初步确定掺铒光纤长度的优化范围;理论研究了反射镜反射率对光源性能的影响,计算出最佳反射率并模拟了该反射率下光源的输出光谱;实验研究了抽运功率对光源平均波长的影响,确定了优化的抽运功率范围,并进一步确定了掺铒光纤的优化长度。实验选用110mW抽运功率,13.74m掺铒光纤,获得了输出功率为46.9mW的高功率光纤光源,其抽运转换效率可达42.6%,且光源保持了约34.54nm的宽带宽。     

自制宽带光源及其在光纤光栅制作中的应用

在光纤光栅制作过程中,宽带光源经常被应用于在线监测光纤光栅的反射率,以便适时有效地控制生成的光栅的透射率的高低程度.利用中心波长为971nm的半导体激光器抽运一段Yb+掺杂双包层光纤,制作出了一个宽带超荧光光源,该光源在最大功率输出时谱宽达到了75nm,并在1085nm附近10nm范围内荧光谱的输出功率高,有较好的光谱平坦性.还利用该宽带光源作为光纤光栅制作的监控光源,制作出了单模和多模光纤布喇格光栅,取得了令人满意的实验结果.结果表明,该宽带光源完全可以适应监控光纤光栅制作的需要.     

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.     

Development of the readout system for waveguide multilayer optical card

Waveguide multilayer optical card （WMOC） is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling ＆ processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic （VB） language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor.     

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.     

Collinear phase-matching study of terahertz-wave generation via difference frequency mixed in GaAs and Inp

The collinearly phase-matching condition of terahertz-wave generation via difference frequency mixed in GaAs and InP is theoretically studied. In collinear phase-matching, the optimum phase-matching wave hands of these two crystals are calculated. The optimum phase-matching wave bands in GaAs and lnP are 0.95-1.38μm and 0.7-0.96μm respectively. The influence of the wavelength choice of the pump wave on the coherent length in THz-wave tuning is also discussed. The influence of the temperature alteration on the phase-matching and the temperature tuning properties in GaAs crystal are calculated and analyzed. It can serve for the following experiments as a theoretical evidence and a reference as well.     

Effects of the alloy compositions on the phonon-polaritons in ternary mixed crystals

Composition dependence of bulk and surface phonon-polaritons in ternary mixed crystals are studied in the framework of the modified random-element-isodisplacement model and the Bom-Huang approximation. The numerical results for Several Ⅱ - Ⅵ and Ⅲ- Ⅴ compound systems are performed, and the polariton frequencies as functions of the compositions for ternary mixed crystals AlxGa1-xAs, GaPxAS1-x, ZnSxSe1-x, GaAsxSb1-x, GaxIn1-xP, and ZnxCd1-xS as examples are given and discussed. The results show that the dependence of the energies of two branches of bulk phonon-polaritons which have phonon-like characteristics, and surface phonon-polaritons on the compositions of ternary mixed crystals are nonlinear and different from those of the corresponding binary systems.     

New insert layer structure OLEDs

An insert layer structure organic electroluminescent device（OLED） based on a new luminescent material （Zn（salen）） is fabricated. The configuration of the device is ITO/CuPc/NPD/Zn（salen）/Liq/LiF/A1/CuPc/NPD/Zn（salen）/Liq/LiF/A1. Effective insert electrode layers comprising LiF（1nm）/Al（5 nm） are used as a single semitransparent mirror, and bilayer cathode LiF（1 nm）/A1（100 nm） is used as a reflecting mirror. The two mirrors form a Fabry-Perot microcavity and two emissive units. The maximum brightness and luminous efficiency reach 674 cd/m^2 and 2.652 cd/A, respectively, which are 2.1 and 3.7 times higher than the conventional device, respectively. The superior brightness and luminous efficiency over conventional single-unit devices are attributed to microcavity effect.