The chapter reviews properties and applications of linear semiconductor optical amplifiers (SOA). Section 12.1 covers SOA basics, including working principles, material systems, structures and their growth. Booster or inline amplifiers as well as low-noise preamplifiers are classified. Section 12.2 discusses the influence of parameters like gain, noise figure, gain saturation, gain and phase dynamics, and alpha-factor. In Sect. 12.3, the application of a linear SOA as a reach extender in future access networks is addressed. The input power dynamic range is introduced, and measurements for on-off keying and phase shift keying signals are shown. Section 12.4 presents the state of the art for commercially available SOA and includes a treatment of reflective SOAs (RSOA) as well.

关键词：电子信息；半导体；光纤；放大器

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This chapter reviews recent technological progress in the development of ultrafast light sources for achieving small footprint and low-power consumption optical transceivers. The focus is on various important light sources, for example, directly modulated diode lasers with high optical-gain materials, low-chirp externally modulated diode lasers, and ultrafast diode lasers with new structure and modulation scheme. The coverage of the topics starts with an in-depth theoretical treatment of key characteristics and dependences, illustrates typical realizations of ultrafast diode lasers and integrated laser-modulators, and includes relevant operation and performance characteristics as well.

关键词：电子信息；半导体；激光源；超速

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A common development task is to take a behavior exercised in a single function (e.g., a failing unit test), and to produce an input to the entire program (a system test) with the same behavior. In security, when the behavior is a potential vulnerability, this is constructing a proof-of-concept exploit. This task is challenging because it requires precise reasoning over an entire program. To automate instances of this task, our approach uses symbolic execution to generate program inputs that undergo transformations before they are used. Using information about the relationship of data structures and transformations in a program, our approach works backward, one transformation at a time, and applies optimized symbolic execution to search for transformation pre-images. Our techniques out-perform standard symbolic execution by several orders of magnitude, and construct exploits against two vulnerable document-processing applications without using source code.

关键词：系统测试；符号执行；数据结构转化；

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Estimating the running time, number of qubits and other resources needed by realistic models of quantum computers is the rst necessary step to reducing these resource requirements. This report describes our Quantum Resource Estimator (QuRE) toolbox which we used to calculate resource estimates for a cross product of several quantum algorithms, quantum technologies, and error-correction techniques. The focus of this work is on the estimation methodology, overhead caused by error correction, and the software tools that we developed. Our toolbox simulates error correction with the Steane code [1, 2], Bacon-Shor code, Knill's post-selection scheme, and surface code, representing codes from both the concatenated and topological error-correcting code families.

关键词：量子计算；量子资源估计工具箱；估算

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This work studies the revenue-maximizing auction of a single block of spectrum that can be awarded either for exclusive licensed use by one operator or reserved for unlicensed use. A number of operators bid for exclusive licensed use and a group of non-colluding agents bid to keep the spectrum unlicensed. The revenue of this auction is compared to that of a Vickrey-Clarke-Groves (VCG) auction and that of another auction recently proposed.

关键词：收入最优化；代理商；无牌谱

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We ask whether strictly causal components form well de ned systems when arranged in feedback con gurations. The standard interpretation for such con gurations induces a xed-point constraint on the function modelling the component involved. We de ne strictly causal functions formally, and show that the corresponding xed-point problem does not always have a well de ned solution. We examine the relationship between these functions and the functions that are strictly contracting with respect to a generalized distance function on signals, and argue that these strictly contracting functions are actually the functions that one ought to be interested in. We prove a constructive xed-point theorem for these functions, introduce a corresponding induction principle, and study the related convergence process.

关键词：严格因果分量；反馈配置；定点理论；函数

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A challenging problem in dissent networking is that of circumventing large-scale communication blackouts imposed by oppressive governments. Although prior work has not focused on the need for user anonymity, we contend that it is essential. Without anonymity, governments can use communication networks to track and persecute users. A key challenge for decentralized networks is that of resource allocation and control. Network resources must be shared in a manner that deprioritizes unwanted traffic and abusive users. This task is typically addressed through reputation systems that conflict with anonymity. Our work addresses this paradox: We prioritize resources in a privacy-preserving manner to create an attack-resilient, anonymity-preserving, mobile ad-hoc network. Our prioritization mechanism exploits the properties of a social trust graph to promote messagesre layed via trusted nodes. We present Rangzen,a microblogging solution that uses smartphones to opportunistically relay messages among citizens in a delay-tolerant network (DTN) that is independent of government or corporatecontrolled infrastructure.

关键词：通信通电；分散网络；RANGZEN

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The tremendous success of Internet services has led to the rapid growth of Warehouse-Scale Computers (WSCs). The networking infrastructure has become one of the most vital components in a datacenter. With the rapid evolving set of workloads and software, evaluating network designs really requires simulating a computer system with three key features: scale, performance, and accuracy. To avoid the high capital cost of hardware prototyping, many designs have only been evaluated with a very small testbed built with off-the-shelf devices, often running unrealistic microbenchmarks or traces collected from an old cluster. Many evaluations assume the workload is static and that computations are only loosely coupled with the very adaptive networking stack. We argue the research community is facing a hardware-software co-evaluation crisis.In this dissertation, we propose a novel cost-efficient evaluation methodology, called Datacenter-in-a-Box at Low cost (DIABLO), which uses Field-Programmable Gate Arrays (FPGAs) and treats datacenters as whole computers with tightly integrated hardware and software. Instead of prototyping everything in FPGAs, we build realistic reconfigurable abstracted performance models at scales of O(10,000) servers. Our server model runs the full Linux operating system and open-source datacenter software stack, including production software such as memcached. It achieves two orders of magnitude simulation speedup over software-based simulators. This speedup enables us to run the full datacenter software stack for O(100) seconds of simulated time. We have built a DIABLO prototype of a 2,000-node simulated cluster with runtime-configurable 10 Gbps interconnect using 6 multi-FPGA BEE3 boards.

关键词：网络基础设施；网络评估；模拟集群

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Since the beginnings of the semiconductor revolution, device engineering and material development have been deeply interconnected. Innovations in one invariably spurred development in the other. One of the most important current challenges are developing techniques which enable deposition of materials on arbitrary substrates and the design constraints of devices fabricated via these techniques. This thesis focuses on furthering the materials development-device design cycle for three techniques: (i) epitaxial lift-off, (ii) nanowire growth via the vapor-liquid-solid growth mode, and (iii) the thin-film vapor-liquid-solid growth technique. The physics of devices made via (i) and (ii) are discussed in chapters two and three, the material science of (iii) is discussed in chapter four, and a method to engineer the physical and electronic properties of individual nanowires made via (ii) is discussed in chapter two deals with the device physics and performance of ultra-thin compound semiconductor on insulator field effect transistors. Due to its excellent electron transport properties, InAs is used as the material of choice for the transistors, termed XOI FETs. These devices are fabricated utilizing an epitaxial layer transfer technique, enabling highly lattice mismatched single-crystalline layers of InAs to be deposited on Si wafers. Allowing devices which combine the excellent transport properties of compound-semiconductors and the established processing infrastructure for silicon. Chapter three discusses the design constraints and guidelines for nanopillar photovoltaics, specifically those fabricated utilizing the CdS/CdTe material system. Critically, the materials parameters that are favorable to non-planar cells are discussed, and the performance expectations for CdS/CdTe nanopillar photovoltaics are discussed.

关键词：器件物理；材料科学；技术发展

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We describe and analyze a novel symmetric triangular factorization algorithm. The algorithm is essentially a block version of Aasen’s triangular tridiagonalization. It factors a dense symmetric matrix A as the product A = PLTLTPT where P is a permutation matrix, L is lower triangular, and T is block tridiagonal and banded. The algorithm is the first symmetric-indefinite communication-avoiding factorization: it performs an asymptotically optimal amount of communication in a two-level memory hierarchy for almost any cache-line size. Adaptations of the algorithm to parallel computers are likely to be communication efficient as well; one such adaptation has been recently published. The current paper describes the algorithm, proves that it is numerically stable, and proves that it is communication optimal.

关键词：三角分解算法；对称不定分解；通信量；最佳通信

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