Experimental demonstration of 10 Gbit/s transmission with an optical backplane system using optical slots

A practical optical backplane system was prepared with transmitter-receiver processing boards and an optical backplane made from polymeric-waveguide-embedded optical printed-circuit boards. Optical slots were used as connection components between the transmitter-receiver processing boards and the backplane board to permit easy and repeatable insertion and extraction of the boards with micrometer precision. We report 10 Gbit/s data transmission between an optical backplane and the transmitter-receiver processing boards.     

A terabit capacity passive polymer optical backplane based on a novel meshed waveguide architecture

An optical backplane based on a meshed polymer waveguide architecture enabling high-speed board-to-board optical interconnection is presented. This planar array of multimode polymer waveguides can provide passive strictly non-blocking links between server line cards fitted with optical transmitter and receiver arrays. This architecture offers a scalable and low-cost solution to the bandwidth limitations faced by electrical backplanes and is suitable for PCB integration. The reported backplane demonstrator uses a matrix of 100 waveguides each capable of 10 Gb/s operation to interconnect 10 cards for a total capacity of a terabit per second aggregate data rate in multicast mode. Characterisation of the backplane demonstrator reveals low link losses of 2 to 8 dB for a multimode fibre input and crosstalk values below −35 dB. Error free data transmission at 10 Gb/s is achieved with a power penalty of only 0.2 dB at a bit-error-rate of 10⁻⁹. Additionally, lossless operation of a Gigabit Ethernet link over the backplane is achieved even when using the worst-case highest loss links.     

导板光互连光斑位置偏移的研究

随着人们对信息处理与交换速度和容量提出的更高的要求,出现了光互连．它具有并行处理、传播速度快、信息量大、空间频带宽、串音小和能量损耗低等优点,因此它在光计算机和信息处理领域中成为越来越吸引人的课题［１～４］提出光电结合的计算机系统．实现光－电混合计算．ＳａｕｅｒＦ提出了将电子元件组成的电路板安装在光导板上的方法［５,６］．每个电路板除了包括计算机本身要求的功能外,还装上发射信号的光源和接收信号的探测器,借助全息元件的耦合,以光导板作为光信息交换的通道．这种互连方式传输信息,结合光电优点,利用Ｂｒ…     

Study on dense multi-fiber backplane for a large-scale switching system

Dense multi-fiber backplane has great prospect in large-scale multi-rack connection system and optical Routers next generation as connecting equipment. The operation principle of multi-fiber backplane is presented in this paper. In order to conquer the difficulties in producing and upgrading the backplane with dense multi-fibers, starting from the traditional crossbar structure in switching backplane, an original method for optimizing the configuration of fiber circuit on backplane is adopted, and applied to the preparation of backplanes. An experimental setup and flow of producing are also proposed to predigest the process of producing. The advantage of this proposed method in maintaining and upgrading the backplane is proved through the achievement of two sample backplanes with 8(×8) × 8(×8) and 12(×8) × 8(×12) configuration and their testing results.     

一种多通道光电系统视轴平行度调校装置

为了获得红外、可见光及微光等不同波段靶标的图像,提出一种多通道光电系统视轴平行度调校装置。该装置能够方便地加载多通道光电探测系统,主要通过下底板的腰形孔间隙及垫修下底板来实现光电探测系统视轴平行度方位及俯仰方向的调校,使其视轴平行度达到15;该装置只需首次调整光学系统的视轴平行度,光电探测系统重复更换镜头后重复定位精度优于0.01 mm。同时装置可方便地加载于光电转台等其他设备上,便于外场试验,满足使用要求。     

Optical interconnect based on a fibre bus

A technology which may form a powerful optical interconnection scheme based on a bus architecture is presented. It is shown that the fibre array connectors involved require alignment tolerances comparable to those of present electrical connectors. Further system flexibility can be obtained by tailoring the connector wavelength characteristics. Results of an experiment, where distributed amplification within the backplane of an optical bus was used to compensate for the power removed at the access points, are also presented. This allows a significantly higher number of output ports to be served than would be possible using a passive bus. As an example application, the feasibility of using the technology as the backplane interconnection in a card and rack system is demonstrated. Extension to a switching scheme using the multi-dimensional optical network concept is described.     

Fast generation of controllable equal-intensity four beams based on isosceles triangle multilevel phase grating realized by liquid crystal spatial light modulator

Liquid crystal spatial light modulator (LCSLM) realizing equal-intensity multiple beams often has some features, i.e., phase valley between two adjacent pixels, flyback region when phase decreases immediately from 2π to 0, and inevitable backplane curvature, which are different from those of most conventional diffractive optical elements (DOEs), such as static DOEs. For optimal intensity uniformity, equal-intensity multi-beam generation must be considered for these artifacts. We present a tunable-grating method in which the intensity uniformity can be improved by considering the LCSLM artifacts. For instance, tuning phase modulation depth of the grating, called isosceles triangle multilevel phase grating (ITMPG), can be used not only to improve the intensity uniformity, but also to fast steer four beams with narrow beamwidths, determined by the same effective aperture of ITMPG. Improved intensity uniformity and high relative diffraction efficiency are demonstrated through experiments with phase-only LCSLM.     

Engineered pixels using active plasmonic holograms with liquid crystals

Digital holography requires arrays of small reconfigurable elements to achieve complex reconstruction of the hologram with common systems based on pixels utilizing liquid crystal on silicon (LCoS) technology. The backplane of a typical pixel element is potentially underutilized and thus relatively large physical areas exist in which information can be stored and exploited to give additional functionality to pixel elements. Polarisation and wavelength dependent optical properties can be achieved in small areas using the plasmonic effects of optical antennae. The integration of LCs with optical antennae‐based plasmonic holograms allows active modulation of the far field pattern. The work here demonstrates the concept that conventional LCoS pixel elements can be greatly enhanced with the integration of plasmonic holograms, composed of optical antennae patterned on the surface, giving rise to new levels of modulation capability for holographic pixel elements. Using LCs, polarisation dependent effects in plasmonic holograms can be switched. ‘Engineered pixels', with sub‐wavelength multiplexing over both polarisation and wavelength, can increase the channel capacity of a typical LC display device. (© 2015 WILEY‐VCH Verlag GmbH &Co. KGaA, Weinheim)     

Demonstration of the centralized optical backplane architecture in a three-board microprocessor-to-memory interconnect system

A prototype of a novel interconnection architecture called the centralized optical backplane (COB) was experimentally demonstrated in a three-board microprocessor-to-memory interconnect system. COB keeps the advantages of bus architecture while at the same time providing uniform optical signal fan-outs. In the prototype, the required connectivity for the microprocessor-to-memory interconnect was achieved by using a COB. The optoelectronic interface modules were optimized to support high-speed processing elements at data rates up to 1.25 Gbps. This demonstration illustrates the conceptual design of the COB and its feasibility in real systems.     

Optical interconnection in embedded-fiber printer circuit boards

Optical interconnection between vertical cavity surface emitting laser (VCSEL) and PIN on fiber-embedded printed circuit board (PCB) was studied in this paper. The whole project was introduced, and the technics by traditional manufacture machine of PCB was described in detail. Model of direct coupling structure between optical transceiver and fiber was analyzed by geometrical optics, and alignment tolerances were given. Performance parameters were tested. It was shown that the advantages of this method were low insertion loss, small size, big throughput, and compatible with traditional technics. It also could have a great application in fabrication of fiber interconnection backplane.     

Digital-to-analog image conversion with an optically addressed spatial light modulator

The possibility of using ferroelectric liquid-crystal optically addressed spatial light modulators to transfer images from silicon backplane devices is investigated. We propose a drive scheme for optically addressed spatial light modulators to perform digital-to-analog image conversion based on the speed performances of current and future silicon backplane devices and on temporal averaging. The validity of the drive scheme is experimentally demonstrated with a LED used to encode the gray levels, and we discuss the performance of the display system.     

Spin-cast planarization of liquid-crystal-on-silicon microdisplays

A simplified method for planarizing liquid-crystal-on-silicon (LCOS) backplanes is presented. The method relies on the planarizing capability of spin-cast benzocyclobutene (BCB) polymeric resin. BCB planarization shows a sixfold reduction in step height on the surface of a typical LCOS backplane. Contact with the underlying pixel circuitry is made by dry etching through openings in the BCB layer. Reflective metal (87% reflectivity) is deposited over the planarized surface and patterned to form high-aperture-ratio pixel mirrors (84%). An average resistance of 0.75 Omega per via was achieved with 3.6-microm-diameter vias in 2-microm-thick BCB. The method and the results of this LCOS backplane planarization and postprocessing are described.     

Fabrication and implementation of large-area organic light-emitting-diode devices on direct patterned backplanes

In this paper, we report on a new cost-effective fabrication technology for large-area organic light-emitting diode (OLED) devices that we have developed. We fabricated OLED lighting devices on a directly patterned backplane using a dry process without employing conventional photolithography patterning technology. The indium–tin-oxide (ITO) anode, metal cathode, insulator, and emissive organic layer patterns were all formed directly on the substrates during the sputtering and evaporation steps by using a shadow mask without using etching or lift-off methods. We fabricated and characterized green phosphorescent emission OLED devices with an emission area of 30 × 120 mm², based on backplanes formed by direct patterning technology. Application of direct patterning technology reduced the total number of processing steps to 4 from the 26 steps required by conventional photo-patterning technology, making it possible to reduce large-scale production cost. Although the process steps were reduced considerably, the typical characteristics were comparable to those of photo-patterned OLEDs. Furthermore, the lifetime of the OLEDs based on direct patterned backplane was observed to be 27,200 h, which is approximately 97% of the lifetime of conventionally patterned OLEDs.     

High‐performance In–Zn–O thin‐film transistors with a soluble processed ZrO2 gate insulator

Spin‐coated zirconium oxide films were used as a gate dielectric for low‐voltage, high performance indium zinc oxide (IZO) thin‐film transistors (TFTs). The ZrO₂ films annealed at 400 °C showed a low gate leakage current density of 2 × 10^–8 A/cm² at an electric field of 2 MV/cm. This was attributed to the low impurity content and high crystalline quality. Therefore, the IZO TFTs with a soluble ZrO₂ gate insulator exhibited a high field effect mobility of 23.4 cm²/V s, excellent subthreshold gate swing of 70 mV/decade and a reasonable I_on/off ratio of ～10⁶. These TFTs operated at low voltages (～3.0 V) and showed high drain current drive capability, enabling oxide TFTs with a soluble processed high‐k dielectric for use in backplane electronics for low‐power mobile display applications. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Integrable optical geometry

It is shown that a Lorentzian 4-manifold admitting a congruence of optical (null) geodesics without shear and twist defines an optical geometry which is integrable (locally flat) in the sense of the theory of G-structures. The existence of a symmetric linear connection compatible with the optical geometry is another condition equivalent to the integrability of the optical G-structure.     

A sandwiched flexible polymer mold for control of particle-induced defects in nanoimprint lithography

Particle related defects are one of the key concerns for nanoimprint lithography, since the particle can amplify the defect to become much larger than the particle itself. We developed a flexible tri-layer mold for control of particle-induced defects. The mold was composed of a PDMS cushion layer sandwiched between a rigid imprint pattern layer and a plastic polyethylene terephthalate (PET) backplane. The PET foil was used as the backplane of the mold to protect the sticky PDMS surface. The PDMS as a cushion layer could locally deform to conform the shape of substrate due to its high elasticity. The multifunctional epoxysiloxane was used for the formation of an imprint layer because of its insensitivity toward oxygen during curing, high transparency, excellent mechanical strength and high resistance to oxygen plasma after cross-linking. Nanostructures with different geometries and sizes were faithfully duplicated by this mold through a UV-curing imprint process. The particle-induced defectivity was dramatically improved by the deformation of the PDMS cushion layer with a slight external pressure. 500 nm pitch grating structures were successfully imprinted on a microposts array surface, both the top and the intervening bottom portions between the microposts.     

一种测量GaAs-GaAlAs行波激光放大器增益特性的实验方法

本文报导了一种测量光耦合效率η的新实验方法。这个方法是建立于p-n结短路光电流原理上的。本文推导出适合于行波激光放大器的光耦合效率的公式。短路光电流用一检流计测量,利用公式获得光耦合效率的实验值。利用实验所测光耦合效率,测量了行波激光放大器的增益随注入电流变化的规律,其结果和实验符合。另外本文还介绍了在脉冲注入电流条件下测行波半导体激光放大器增益的实验方法。     

级联型四能级原子相干介质中的光学双稳态和多稳态

主要研究了在一单向环形腔内的级联型四能级原子被三个光场驱动的光学双稳态和多稳态行为. 三个单模光场通过三个光子跃迁路径与原子系统耦合. 在这种情况下,中间两能级间所加的耦合场Ω_B变得非常重要. 研究显示耦合场Ω_B的增加会使光学双稳态的阈值减小,同时也会导致光学多稳态的产生.对上面两能级间所加的耦合场的作用也进行了讨论,同时还讨论了探测场失谐和合作参数对光学双稳态及多稳态的影响. 关键词： 原子相干 光学双稳态和多稳态 四能级原子     

Design of Plane-Symmetric Low <Emphasis Type="Italic">F</Emphasis>-number Reflective System Based on Perturbation Aberration Model

All-reflective optical systems have theoretically no chromatic aberration and are suitable for wide spectral application, but co-axial reflective systems are difficult to design as low F-number optical systems. In this paper, the aberration of plane-symmetric optical systems with low F-number is analyzed based on the wavefront derived from optical path length. Up to third-order aberrations are classified into three categories by their characteristics. The reduction method of the dominant aberration, astigmatism-like aberration, is proposed. In the method, the Gauss image plane is modeled by means of a simplified mirror surface with third-order approximation. Because the system is plane-symmetric, symmetric cross section and asymmetric cross section are modelled differently. The design example of a three-mirror system with F/2 is shown.     

Spatial coherence properties of light from optical fibres

The mutual intensity of the optical field in the Fraunhofer diffraction region produced from the end of an optical fibre under illumination of a coherent beam, is theoretically analysed by using an optical fibre-end source model. In this source model, the optical field at the end of the fibre is expressed as an aggregation of independent plane waves with random directions and phases, because the guided modes propagating through the fibre may be regarded as a stochastic process. It is found that the optical field in the diffraction region from the multimode optical fibre is not homogeneous butquasi homogeneous in a statistical sense. The spatial coherence properties in the field are discussed in connection with theV number (the normalized frequency) of the fibre and in comparison with those in the field produced from an incoherent source obeying the van Cittert-Zernike theorem.