The 8×10 GHz Receiver Optical Subassembly Based on Silica Hybrid Integration Technology for Data Center Interconnection

An 8×10 GHz receiver optical sub-assembly （ROSA） consisting of an 8-channel arrayed waveguide grating （AWG） and an 8-channel PIN photodetector （PD） array is designed and fabricated based on silica hybrid integration technology. Multimode output waveguides in the silica AWG with 2% refractive index difference are used to obtain fiat-top spectra. The output waveguide facet is polished to 45° bevel to change the light propagation direction into the mesa-type PIN PD, which simplifies the packaging process. The experimentM results show that the single channel I dB bandwidth of AWG ranges from 2.12nm to 3.06nm, the ROSA responsivity ranges from 0.097 A/W to 0.158A/W, and the 3dB bandwidth is up to 11 GHz. It is promising to be applied in the eight-lane WDM transmission system in data center interconnection.

Networking Technologies Based on IEEE 802.16 and WiMAX

It is a difficult problem to improve network performance and resource utilization efficiency in wireless communications. As a standard of broadband wireless access systems, IEEE 802.16 adopts Orthogonal Frequency Division Multiplexing (OFDM) and multi-modulation/coding techniques at the physical layer, combines contend and pre-contract mechanisms at the Medium Access Control (MAC) layer. Based on the QoS-related concepts such as connection and service flow, IEEE 802.16 optimizes network entry and initialization, and frame format in order to improve network throughput, reduce network delay, and increase the flexibility of network configuration. Based on IEEE 802.16, WiMAX adopts Point-to-Multipoint (PMP) network topology to realize flexible networking. It is a typical application technology of broadband wireless access systems.

Twin-Field Quantum Key Distribution Protocol Based on Wavelength-Division-Multiplexing Technology

Quantum key distribution(QKD) generates information-theoretical secret keys between two parties based on the physical laws of quantum mechanics. Following the advancement in quantum communication networks, it becomes feasible and economical to combine QKD with classical optical communication through the same fiber using dense wavelength division multiplexing(DWDM) technology. This study proposes a detailed scheme of TF-QKD protocol with DWDM technology and analyzes its performance, considering the influence of quantum channel number and adjacent quantum crosstalk on the secret key rates. The simulation results show that the scheme further increases the secret key rate of TF-QKD and its variants. Therefore, this scheme provides a method for improving the secret key rate for practical quantum networks.

A Single Mode Hybrid Ⅲ-Ⅴ/Silicon On-Chip Laser Based on Flip-Chip Bonding Technology for Optical Interconnection

A single mode hybrid Ⅲ-Ⅴ/silicon on-chip laser based on the flip-chip bonding technology for on-chip optical interconnection is demonstrated. A single mode Fabry-Perot laser structure with micro-structures on an InP ridge waveguide is designed and fabricated on an InP/AIGaInAs multiple quantum well epitaxial layer structure wafer by using i-line lithography. Then, a silicon waveguide platform including a laser mounting stage is designed and fabricated on a silicon-on-insulator substrate. The single mode laser is flip-chip bonded on the laser mounting stage. The lasing light is butt-coupling to the silicon waveguide. The laser power output from a silicon waveguide is 1.3roW, and the threshold is 37mA at room temperature and continuous wave operation.

Cognition Based Reconfigurable Wireless Network Technology

The End-to-End Reconfigurability (E2R) project aims at realizing the convergence of the heterogeneous radio networks and the optimal utilization of the radio resources. With the continuous development of E2R technology and cognitive theory, the evolution from existing radio networks to future reconfigurable radio networks with the cognitive ability becomes possible. Nowadays the research aspects of E2R include the system architecture of reconfigurable radio networks and some key technologies for their evolution.

IPv4 Based Reliable Mobile Multicast Technology

The mobile multicast technology has been a research hotspot in the wireless Internet field in recent years.Quite a large part of its applications requires the reliability in a mobile environment to be equivalent to that provided by wireline links.However,the inherent features of a mobile environment,that is,high error rate of links and dynamically changing multicast members’ locations,are great difficulties for mobile multicast,let alone reliable mobile multicast.The IPv4-based reliable mobile multicast algorithms come with two different design philosophies.A part of the algorithms is to be improved for better reliability by solving existing algorithm-related problems;while other algorithms are to implement reliable mobile multicast with new function entities introduced to guarantee reliability.

Production base of annual 3000 tons sintered NdFeB of SinoMagnetics Technology goes into operation

Sino magnetics technology is a high-tech enterprise specializing in R&D and production of rare earth permanent magnet materials.It is reported that the enterprise has accelerated the construction of annual3000 tons of high performance sintered NdFeB production base,and the construction of the base has been completed and put into use.

Eco－environmental information system of Tianjin City─Design，implementation and applications

This paper describes the design, implementation and applications of theeco-environmental information system in Tianjin City, which is the kernel of the decision support sys-tem for urban eco-environmental regulation (DSSUER) The design of this information system isbased on the analysis of the requirements of users. The system features that it has expendability,maintainability and universality, makes data be shared between different components of DSSUERand provides help facilities and protection. The system is built by using database and graphic basetechnologies it consists of the main control module, data-management module and data-proassingniodule. The applications of this system is demonstrated by an example which is the case ofsuitability analysis of land use for residential areas in Tianjin.

Expanding the US-China cooperation on service programs： New opportunities for both countries

For years, the US and China have cooperated closely on manufacturing programs, which helps China become the world manufacturing center. While they both have gained much from the cooperation, there are also increasing frictions, disputes, complains and dissatisfaction with each other because of the huge trade unbalance problem and other significant issues. The US is eager to expand export to China, but China seems hesitating to decide what to import from the US. This paper presents an analysis about the benefits of the US-China cooperation with a primary focus on the service sector, which remains a large and untapped opportunity for China. The goal of the paper is to explore a new route to relieve the trade balance issues as they separately impact both nations. While focusing on analyzing several immediate opportunities, the paper also investigates several new ideas that rest on technology as well as entrepreneurial development.

Measuring method for micro-diameter based on structured-light vision technology

Based on structured-light vision measurement technology, we study a measuring method for microdiameter. The measurement principle and mathematical model are described. A novel grayscale barycenter extraction algorithm along the radial direction is proposed, which can precisely gather the image coor- dinates of the ellipse-shaped light-stripe centers. The accuracy of the measurement result shows marked improvement by using the algorithm. The method executes circle fitting to the measured three-dimensional （3D） data using linear least square method, which can acquire the diameter, surface profile, and other information of the object effectively. On the scene, a line-structured light vision system using the presented method is applied to measure the curvature radius of metal blades. Experimental results show that the measurement precision of the system is higher than 2 μm.

Liquid crystal depolarizer based on photoalignment technology

We propose a depolarizer based on the principle of a collection of half-wave plates with randomly distributed optic axes. The design is demonstrated by means of dynamically photopatterning liquid crystal into randomly aligned homogeneous domains. We characterize the liquid crystal depolarizer for 1550 nm and C-band(1520–1610 nm). A degree of polarization of less than 5% is obtained for any linearly polarized light. This study provides a practical candidate for high-performance depolarizers.

A lattice measuring method based on integral imaging technology

Aiming at the problem that the lattice feature exceeds the view field of the scanning electron microscope(SEM)measuring system,a new lattice measuring method is proposed based on integral imaging technology.When the system works,the SEM measuring system is equivalent to an integral image acquisition system.Firstly,a lattice measuring method is researched based on integral imaging theory.Secondly,the system parameters are calibrated by the VLSI lattice standard.Finally,the value of the lattice standard to be tested is determined based on the calibration parameters and the lattice measuring algorithm.The experimental results show that,compared with the traditional electron microscope measurement method,the relative error of the measured value of the algorithm is maintained within 0.2%,with the same level of measurement accuracy,but it expands the field of view of the electron microscope measurement system,which is suitable for the measurement of samples under high magnification.

Towed line array sonar platform noise suppression based on spatial matrix filtering technology

The spatial matrix filter was designed and used for solving the problem to detect a weak target who was influenced by the strong nearby platform noise interference of the towed line array sonar. The MFP technology and the DOA estimation technology were combined together by using the sound propagation characteristics of both target and interference. The spatial matrix filter with platform noise zero response constraint was designed by the near-field platform noise normal modes copy vectors and the far-field plane wave bearing vectors together. The optimal solution of the optimization problem for designing the spatial matrix filter was deduced directly, and it was simplified by the generalized singular value decomposition. The total response error to the plane wave bearing vectors and the total response to the platform noise copy vectors were given. The phenomena that strong interferences existed in the bearing course and blind areas existed after filtering were analyzed by the correlation between the plat- form noise copy vectors and the plane wave bearing vectors. It could be found from simulations that it has less blind area and higher detection ability by using the spatial matrix filtering technology.

Dark-field detection method of shallow scratches on the super-smooth optical surface based on the technology of adaptive smoothing and morphological differencing

In recent years, modern optical processing technologies, such as single point diamond turning, ion beam etching, and magneto-theological finishing, arc getting break- throughs. Machining precisions of super-smooth optics have also been significantly improved. However, with increasing demands for the optical surface quality,

Multi-Wavelength Optical Packet Routing Technologies Based on Superstructured Fiber Bragg Gratings

A WDM compatible Edge-to-Edge Self-Routed optical packet switched network that simplifies the optical processing is proposed. The system employs all-optical packet label generation and recognition using coded superstructured Fiber Bragg gratings.

Study on the key technology of spectral reflectivity reconstruction based on sparse prior by a single-pixel detector

By studying the traditional spectral reflectance reconstruction method, spectral reflectance and the relative spectral power distribution of a lighting source are sparsely decomposed, and the orthogonal property of the principal component orthogonal basis is used to eliminate basis; then spectral reflectance data are obtained by solving a sparse coefficient. After theoretical analysis, the spectral reflectance reconstruction based on sparse prior knowledge of the principal component orthogonal basis by a single-pixel detector is carried out by software simulation and experiment. It can reduce the complexity and cost of the system, and has certain significance for the improvement of multispectral image acquisition technology.

DWDM Devices Based on Planar Waveguide Technologies

A review is presented on some of our recent results for designs, simulations and fabrication of several photonic integrated devices, such as arrayed-waveguide gratings (AWGs) and etched diffraction gratings (EDGs), based on planar waveguide technologies. Some novel designs for flat-top AWGs and EDGs with flat-top spectral responses are presented.

Photonic integrated circuit components based on amorphous silicon-on-insulator technology

We present integrated-optic building blocks and functional photonic devices based on amorphous siliconon-insulator technology. Efficient deep-etched fiber-to-chip grating couplers, low-loss single-mode photonic wire waveguides, and compact power splitters are presented. Based on the sub-μm photonic wires, 2 × 2 Mach–Zehnder interferometers and add/drop microring resonators(MRRs) with low device footprints and high finesse up to 200 were realized and studied. Compact polarization rotators and splitters with ≥10 d B polarization extinction ratio were fabricated for the polarization management on-chip. The tuning and trimming capabilities of the material platform are demonstrated with efficient microheaters and a permanent device trimming method, which enabled the realization of energy-efficient photonic circuits. Wavelength multiplexers in the form of cascaded filter banks and 4 × 4 routers based on MRR switches are presented. Fabrication imperfections were analyzed and permanently corrected by an accurate laser-trimming method, thus enabling eight-channel multiplexers with record low metrics of sub-m W static power consumption and ≤1°C temperature overhead. The high quality of the functional devices, the high tuning efficiency, and the excellent trimming capabilities demonstrate the potential to realize low-cost, densely integrated, and ultralow-power 3D-stacked photonic circuits on top of CMOS microelectronics.

Analysis of Chinese women with primary ovarian insufficiency by high resolution array-comparative genomic hybridization

Background Primary ovarian insufficiency （POI） is defined as a primary ovarian defect characterized by absent menarche （primary amenorrhea） or premature depletion of ovarian follicles before the age of 40 years. The etiology of primary ovarian insufficiency in human female patients is still unclear. The purpose of this study is to investigate the potential genetic causes in primary amenorrhea patients by high resolution array based comparative genomic hybridization （array-CGH） analysis. Methods Following the standard karyotyping analysis, genomic DNA from whole blood of 15 primary amenorrhea patients and 15 normal control women was hybridized with Affymetrix cytogenetic 2.7M arrays following the standard protocol. Copy number variations identified by array-CGH were confirmed by real time polymerase chain reaction.

Effects of regenerative mechanical vibration on the mechanical integrity of ceramic diesel particulate filters

In this study, the effects of mechanical vibration on the mechanical properties of ceramic diesel particulate filters(DPFs) were investigated. The goal is to determine how the mechanical vibration used in the regenerative ash cleaning process for these filters affects their mechanical integrity during subsequent reuse. Both virgin and vibrated DPF samples were subjected to compressive and 3-point flexural loading at three different loading rates along axial and tangential directions. Statistical analysis was conducted to determine the significance of variation in the compressive and flexural strengths of the DPFs as a result of exposure to mechanical vibration. The results show that there is no statistically significant difference in both compressive and flexural strengths of the virgin DPFs and the DPFs subjected to the same level of mechanical vibration typically used in ash cleaning of DPFs. When the intensity of vibration was doubled, the drop in compressive strength became statistically significant, but less than 10% under axial loading. However, no drop in flexural strength was observed for DPFs subjected to this high intensity of mechanical vibration. The safe threshold for mechanical vibration of ceramic filters is considered to be much higher than that currently used in vibration-based ash cleaning process.