Optimal usage of available wiring resources in diffractive-reflective optoelectronic multichip modules

Advances in VLSI and optoelectronic multichip module technologiesare enabling the construction of ultracompact massively parallelprocessing systems. The technological parameters that define thewirability and delay characteristics of these technologies have asignificant impact on the system architecture. An analytical modelis presented that allows the design space exploration of theinterconnection networks associated with multinode chips packaged on asingle multichip module substrate. Possible system designs areevaluated for a two-level interconnect with separate k-aryn-cube networks for interchip and intrachipcommunication. The impact of several architectural andtechnological parameters on the optimal network implementation (based on average no-load latency) is analyzed.     

基于微机械系统的多芯片组件封装和特性模拟

基于微机械系统(MEMS)的噪声估算,提出了一种可用于微机械系统的多芯片组件(MCM)封装技术,并对封装完成后的信号噪声、输入端相对延时、接收信号的电磁干扰强度等特性进行模拟.仿真结果表明,相对已有MEMS封装技术,本文提出的多芯片组件封装技术具有显著优点.文中封装尺寸182.88mm×121.92mm.     

Dynamic digital photorefractive memory for optoelectronic neural network learning modules

Neural network modules based on page-oriented dynamic digital photorefractive memory are described. The modules can implement two different interconnection organizations, fan-out and fan-in, depending on their target network applications. Neural network learning is realized by the real-time memory update of dynamic digital photorefractive memory. Physical separation of subvolumes in the page-oriented photorefractive memory architecture contributes to the low cross talk and high diffraction efficiency of the stored interconnection weights. Digitally encoded interconnection weights ensure high accuracy, providing superior neural network system scalability. Module scalability and feedforward throughput have been investigated based on photorefractive memory geometry and the photodetector power requirements. The following four approaches to extend module scalability are discussed: partial optical summation, semiparallel feedforward operation, time partitioning, and interconnection matrix partitioning. Learning capabilities of the system are investigated in terms of required interconnection primitives for implementing learning processes and three memory-update schemes. The experimental results of Perceptron learning network implementation with 900 input neurons with digital 6-bit accuracy are reported.     

Matrix partitioning methods for interior point algorithms

We consider here a linear programming problem whose rows of the constraint matrix can be partitioned into two parts. Such natural partitions exist in several special linear programs, including the assignment problem, the transportation problem, the generalized upper-bounded variable problem, the block diagonal linear program; and can also be used to induce sparsity patterns in Cholesky factorizations. In this paper, we propose a matrix partitioning method for interior point algorithms. The proposed method independently generates Cholesky factorizations of each part, and reduces the complexity to that of solving generally, a dense linear system involving several rank one updates of the identity matrix. Here, we propose solving this linear system by an inductive use of the Sherman-Morrison-Woodbury formula. The proposed method is easily implemented on a vector, parallel machine as well as on a distributed system. Such partitioning methods have been popular in the context of the simplex method, where the special structure of the basis matrix is exploited.     

Silicon multichip modules: evolving a high performance technology from low-end applications

Recently, silicon-on-silicon multichip modules (MCMs) have shifted away from high performance digital applications toward low-end, cost driven products with a primary emphasis on volume production. This shift has been accompanied by changes in the physical structure of the MCM interconnections. Cost reduction has driven them toward thinner metal and dielectric layers, and wherever possible toward the use of fewer layers. It has also fundamentally changed the flip-chip attachment process. We are now reexamining the effect these changes are having on the performance characteristics of the technology, and the role of MCMs in systems packaging.     

Computation considerations and fast algorithms for calculating the diffraction integral

Abstract

One of the most basic optical ‘components’ is free-space propagation. A common approximation used when calculating the resultant field distribution after propagation is the Fresnel integral. This integral can be evaluated in two ways: directly or by using the angular spectrum. In this paper, we estimate the regions in which each mode of evaluation is preferable according to computing efficiency and accuracy considerations. A fast numerical algorithm is introduced for each region. The result is relevant also for the evaluation of the Rayleigh-Sommerfeld diffraction formula.     

Design considerations for refrigeration cycles

The Carnot COP, which assumes a thermodynamically ideal cycle in which no irreversibilities exist, is often considered to be a design goal for actual cycles. However, the Carnot COP does not consider heat transfer mechanisms. Heat transfer at a finite rate is necessarily an irreversible process and unavoidable in a refrigeration cycle. The lack of consideration of rate processes reduces the usefulness of the Carnot COP as a realistic design goal. In this paper, the limitations of both thermodynamics and heat transfer are considered to identify a more realistic design goal for the COP of refrigeration cycles. The consideration of heat transfer limitations leads to a design rule for the optimum distribution of heat exchange area between the low- and high-temperature heat exchangers.     

Design considerations for STJ x-ray detectors

The geometrical shape and layer thicknesses of superconducting tunnel junctions (STJ) influence their suitability as x-ray detectors. Examples relating to field biasing are discussed. Two related energy loss mechanisms are also modeled.     

Design considerations for a highly segmented mirror

Design issues for a 30-m highly segmented mirror are explored, with emphasis on parametric models of simple, inexpensive segments. A mirror with many small segments offers cost savings through quantity production and permits high-order active and adaptive wave-front corrections. For a 30-m f/1.5 paraboloidal mirror made of spherical, hexagonal glass segments, with simple warping harnesses and three-point supports, the maximum segment diameter is approximately 100 mm, and the minimum segment thickness is approximately 5 mm. Large-amplitude, low-order gravitational deformations in the mirror cell can be compensated if the segments are mounted on a plate floating on astatic supports. Because gravitational deformations in the plate are small, the segment actuators require a stroke of only a few tens of micrometers, and the segment positions can be measured by a wave-front sensor.     

Design considerations for piezoelectric polymer ultrasound transducers

Much work has been published on the design of ultrasound transducers using piezoelectric ceramics, but a great deal of this work does not apply when using the piezoelectric polymers because of their unique electrical and mechanical properties. The purpose of this paper is to review and present new insight into seven important considerations for the design of active piezoelectric polymer ultrasound transducers: piezoelectric polymer materials selection, transducer construction and packaging requirements, materials characterization and modeling, film thickness and active area design, electroding selection, backing material design, and front protection/matching layer design. Besides reviewing these design considerations, this paper also presents new insight into the design of active piezoelectric polymer ultrasonic transducers. The design and fabrication of an immersible ultrasonic transducer, which has no adhesive layer between the active element and backing layer, is included. The transducer features direct deposition of poly(vinylidene fluoride-trifluoroethylene) [P(VDF-TrFE)] copolymer onto an insulated aluminum backing substrate. Pulse-echo tests indicated a minimum insertion loss of 37 dB and -6 dB bandwidth of 9.8 to 22 MHz (71%). The use of polymer wear-protection/quarter-wave matching layers is also discussed. Test results on a P(VDF-TrFE) transducer showed that a Mylar/sup TM/ front layer provided a slight increase in pulse-echo amplitude of 15% (or 1.2 dB) and an increase in -6 dB pulse-echo fractional bandwidth from 86 to 95%. Theoretical derivations are reported for optimizing the active area of the piezoelectric polymer element for maximum power transfer at resonance. These derivations are extended to the special case for a low profile (i.e., thin) shielded transducer. A method for modeling the non-linear loading effects of a commercial pulser-receiver is also included.     

Polysiloxanes for optoelectronic applications

During the past few years, polysiloxanes have been extensively researched on optimizing the physical and electronic properties of organic polymer semiconductors. Polysiloxanes display their advantages including good solubility in common organic solvents, good film-forming ability, fair adhesion to various substrates and excellent resistance to thermal, chemical and irradiation degradations. In this review, we focus on the fundamental design and synthesis strategies of bonding polysiloxanes with organoelectronic groups. The characterization of polysiloxanes will be briefly introduced. Specifically, we summarize the recent advances of the utilization of polysiloxanes as organic light-emitting diodes (OLEDs), solar cells, electrical memories and liquid crystalline materials. Finally, several perspectives related to polysiloxanes materials for organoelectronic applications are proposed based on the reported progress and our own opinion.     

Design and construction of the high-speed optoelectronic memory system demonstrator

The high-speed optoelectronic memory system project is concerned with the reduction of latency within multiprocessor computer systems (a key problem) by the use of optoelectronics and associated packaging technologies. System demonstrators have been constructed to enable the evaluation of the technologies in terms of manufacturability. The system combines fiber, free space, and planar integrated optical waveguide technologies to augment the electronic memory and the processor components. Modeling and simulation techniques were developed toward the analysis and design of board-integrated waveguide transmission characteristics and optical interfacing. We describe the fabrication, assembly, and simulation of the major components within the system.     

无线传感网3D-MCM封装结构的设计与实现

设计和实现了一种新型的三维多芯片组件(3D-MCM).采用融合了FCOB(flip-chip on board)、COB(chip on board)、BGA(ball grid array)等技术的三维封装(3D packaging)形式,通过倒装焊和引线键合等互连技术在高密度多层有机基板上实现了塑封BGA器件和裸芯片的混载集成.对器件结构的散热特性进行了数值模拟,并对热可靠性进行了评估.实现了电功能和热机械可靠性,达到设计要求并付诸应用.     

Design considerations for the DASTEK 4830 disk drive

The DASTEK 4830 Disk Drive is designed to provide minicomputer original equipment manufacturers (OEM) with direct access storage having the performance, reliability, and cost/MB characteristics of drives attached to large mainframe computers. This was accomplished by utilizing state-of-the -art technologies in the areas of read/write heads, media, data encoding/decoding, and read/write head positioning as well as packaging improvements and microprocessor based electronics.     

Design of compression window algorithms for elimination of errors

An approach based on uniform Markov chains is proposed for estimating the efficiency of a class of window compression-rejection algorithms. The approach makes it possible to calculate windows and to obtain detailed information on the operation of these algorithms.Translated from Izmeritel'naya Tekhnika, No. 10, pp. 12–17, October, 1993.     

Design of ultrasonic array elements for acoustic power considerations

In sound-transmitting applications such as therapeutic ultrasound, the acoustic power at a particular operating frequency is a critical figure of merit for transducer/array design. A design methodology for enhancing the acoustic power radiated from fluid-loaded piezoelectric array elements at a fixed frequency is developed in this paper. A gradient-based optimization algorithm is integrated within the finite element framework to guide the determination of the two design variables, the piezoelectric element thickness and the matching layer thickness, to optimize the acoustic power output. A method for avoiding explicit remeshing in the optimization iteration is presented. Optimized designs are determined numerically, and the effectiveness of the design method is confirmed by experimental measurements. The validated numerical analysis also shows that conventional design strategies using one-dimensional transducer analysis and rule-of-thumb matching layer or protection layer sizing rules may not give the best design for array elements in acoustic power applications     

Design and analysis of an optoelectronic inclinometer for simultaneous measurement of inclinations along two orthogonal directions

Conventional inclination measurement systems such as precision vials and capacitance measuring systems can measure inclination in only one direction at a time. We present what is believed to be a new optoelectronic system that can measure inclination angles along two orthogonal directions simultaneously by using a simple pendulum, two mirrors, a 2D position-sensing detector (PSD), and a laser diode. The light ray from the laser is projected onto a mirror that is fixed to a pendulum whose relative angle modifies in response to inclination changes of the inclinometer's housing. The light ray reflected by the mirror is sensed by the PSD, after which the signal can be interpreted by a PSD signal processor, recorded, or output to a computer. This study uses skew-ray tracing methodology to obtain implicit nonlinear system equations to model the relations of the relative inclination angles of the various components, PSD position, and world frame. A first-order Taylor series expansion is used to obtain a linear form of the system equations. To validate the proposed methodology, an actual prototype system is built and experimental results show that the performance of this system is excellent.     

Design and analysis of a diffractive optical filter for use in an optoelectronic error-diffusion neural network

The design, fabrication, experimental characterization, and system-performance analysis of a diffractive optical implementation of an error-diffusion filter for use in digital image halftoning is reported. A diffractive optical filter was fabricated as an eight-level phase element that diffuses the quantization error nonuniformly in both the weighting and the spatial dimensions, according to a prescribed algorithm. Ten identical diffractive elements were fabricated on ten different wafers and subsequently characterized experimentally. A detailed error analysis including both fabrication and instrumentation errors was carried out to quantify the performance of the fabrication process as well as the expected system performance of the filters. Halftone system performance was evaluated by use of the experimental filter's performance and both quantitative and qualitative performance metrics. The results of this analysis demonstrate that multiple identical copies of a diffractive optical filter can be produced with sufficient accuracy that no loss in the halftoning system performance results.