基于半导体光放大器交叉增益调制(SOA-XGM)波长变换器仿真研究

本文在PTDS(Photonic Transimission Design Suite)软件仿真平台上对基于半导体光放大器交叉增益调制(SOA-XGM)的波长变换器的变换特性作了仿真实验研究,仿真并分析了输入信号光功率、输入探测光功率、偏置电流和SOA的结构参量等因素对变换信号的消光比(ER)、Q值及误码率(BER)的影响关系.研究结果对优化设计SOA-XGM波长变换器有一定的参考价值.     

脉冲光热光谱中波长效应的理论分析

本文从理论上分析了脉冲光热谱中波长效应。讨论了波长调谐对脉冲光热光谱信号的峰值和时间特性的影响。     

32通道16位D/A转换器MAX5631的原理及应用

介绍了美国MAXIM公司的32通道16位D/A转换器MAX5631的基本功能 ,详细讨论了它的三种工作模式及工作时序 ,给出了MAX5631与AT89C51单片机的一种串行接口连接方法 ,同时给出了它们相应的软件程序。     

Burstification Queue Management in Optical Burst Switching Networks

Among the various issues lying in optical burst switching (OBS) networks, burstification, i.e., assembling multiple IP packets into bursts, is an important one. Between the two important aspects related to burst assembly, the burst assembly algorithm aspect has been extensively studied in the literature. However, as far as we know, there is no research about the burstification queue management (BQM) aspect, which refers to how many burstification queues (BQ) we should set at each OBS edge node and how to manage these BQs. Suppose there are G destinations (egress edge nodes) and the OBS network provides S different quality of service (QoS) classes. Traditionally, it is simply regarded that each ingress edge node needs G· S queues to sort incoming packets, one for each possible destination and QoS class. For simplicity, we call this policy the static dedicate BQM (SDB) policy. The SDB policy, though simple, lacks scalability since we have to add S BQs at each OBS edge node if an extra OBS edge node is added to the OBS network. To solve this problem, we propose in this paper two BQM policies: quasi-static BQM (QSB) policy and dynamic BQM (DB) policy. For the QSB policy, we derive the packet loss probability due to lacking BQs based on a Markov chain, from which we can work out the employed number of BQs for a given packet loss probability. Based on these results, the scalability of the QSB policy is also studied. With the DB policy, we not only can dynamically assign BQs for incoming packets, but also can dynamically allocate buffer capacity for each BQ by using a least-mean-square (LMS)-based linear prediction filter. The performance of the DB policy is investigated by analysis and extensive simulations. We also compared the performance of the QSB policy and the DB policy. Results from analysis and simulation demonstrate that the DB policy is the best.     

CWDM Metropolitan Multiple-Access Ring Network Based on Optical Packet Witching

We present a novel CWDM metropolitan multiple-access ring network based on optical switching of packets according to their wavelength. Each node within the MAN is identified by a combination of wavelength and numerical address. Hence, nodes are able to drop packets presenting a particular wavelength and numerical address, but can insert packets in any wavelength into the ring. This configuration allows wavelength sharing, as several nodes are identified by the same wavelength (but different numerical addresses), and simplifies switching requirements since the set of numerical addresses is reduced. We analyze the viability and scalability of such a network, determining the number of nodes supported by the network under different traffic scenarios and wavelength resources. The impact of switching time on network performance is also analyzed in order to determine which switching technology should be employed when implementing the network. An erratum to this article is available at .     

波分多路应用引伸至市内网

本文首先简述从时分多路发展至波分多路的具体过程。接着，详细说明时分多路系统在途径主干线中上的应用，以及最近引伸至市内网和接入网的应用。于是简单提到波分多路技术从点至点系统进而应用于全光通信网。又简述波分多路在海底光缆的应用。     

水的折射率与波长间函数关系的模型

分析的水的折射率模型，并建立了相应的函数关系式，由对可见区提出的理论推导出了一个简单的三项非线性模型，在覆盖紫外到近红外（200-1100nm)的整个扩展波段上与实测数据吻合良好。     

Temperature sensing using the spectral interference of polarization modes in a highly birefringent fiber

The spectral interference of polarization modes in a highly birefringent (HB) fiber to measure temperature is analyzed theoretically and experimentally. A tandem configuration of a birefringent delay line and a sensing HB fiber is considered and the spectral interferograms are modelled for the known birefringence dispersion of the HB fiber under test. As the delay line, a birefringent quartz crystal of a suitable thickness is employed to resolve a channeled spectrum. The channeled spectra are recorded for different temperatures and the polarimetric sensitivity to temperature, determined in the spectral range from 500 to 850 nm, is decreasing with wavelength. It is demonstrated that the temperature sensing is possible using the wavelength interrogation, i.e., the position of a given interference maximum is temperature dependent. The temperature sensitivity of the HB fiber under test is −0.25 nm/K and the resolution is better than 0.5 K.     

Localized surface plasmon resonance: nanostructures, bioassays and biosensing--a review

Localized surface plasmon resonance (LSPR) is an optical phenomena generated by light when it interacts with conductive nanoparticles (NPs) that are smaller than the incident wavelength. As in surface plasmon resonance, the electric field of incident light can be deposited to collectively excite electrons of a conduction band, with the result being coherent localized plasmon oscillations with a resonant frequency that strongly depends on the composition, size, geometry, dielectric environment and separation distance of NPs. This review serves to describe the physical theory of LSPR formation at the surface of nanostructures, and the potential for this optical technology to serve as a basis for the development bioassays and biosensing of high sensitivity. The benefits and challenges associated with various experimental designs of nanoparticles and detection systems, as well as creative approaches that have been developed to improve sensitivity and limits of detection are highlighted using examples from the literature.