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1.
基于半导体光放大器偏振旋转的全光缓存器   总被引:5,自引:2,他引:3  
程木  吴重庆  赵瑞  宋超  李政勇  王亚平 《光学学报》2008,28(10):1898-1902
全光缓存器可实现数据包在光域内的缓存,是全光路由、伞光计算以及全光交换的关键部件之一.提出了一种基于半导体光放大器(SOA)中非线性偏振旋转(PR)的光纤环型全光缓仃器结构;提出了一种利用偏振主态(PSP)寻找两个正交线偏振态以及在线实时测量光纤中偏振态的方法.通过改变SOA的注入电流,实现了对两个正交偏振态转化的控制,利用这两个正交的线偏振态,实现了信号的"写"人和"读"出.利用该结构的缓存器,实现了2.5 Gb/s的1024 bits数据包6圈的缓存.缓存后的信号波形良好.  相似文献   

2.
This paper gives a brief introduction to the various wavelength conversion techniques. In order to explain the applications and benefits of the wavelength conversion techniques in WDM all-optical networks, several analytical models are studied.  相似文献   

3.
An ultrafast photonic asynchronous transfer mode (ATM) switch is proposed that incorporates a holographic buffer memory and an optical parallel routing controller. Ultrafast serial-to-parallel conversion of the temporal profiles of optical cells into spatial patterns is used to process optical cells in space in a parallel manner. The spatial pattern of the data payload is holographically recorded as a page in the optical buffer memory. The routing control to establish the switching state consists of header recognition performed by optical matched filtering, followed by control signal generation via reference to a lookup table. The ultimate throughput of the switch is expected to be 103 Tb/s with line bit-rates of 17 Tb/s.  相似文献   

4.
Recent progress in ultrafast and wideband all-optical processing technologies to realize flexible and transparent optical time-division multiplexing (OTDM)/wavelength-division multiplexing (WDM) photonic networks is reviewed covering ultrafast OTDM technologies handling more than 100 Gbit/s per wavelength channel and wideband WDM technologies handling more than 1000 wavelength channels over the 200 nm range.  相似文献   

5.
To suppress crosstalk caused by matched filtering in label recognition based on optical correlation, we propose the novel design method of a label recognition filter to improve the discrimination performance. Assuming the assistance of optical time-gating, the label recognition filter is designed by a technique of a multiple-object discriminant filter (MODF) so that the crosstalk can be suppressed only at the center of correlation signals. This method can reduce the requirement for the performance of an optical thresholder. Simulation results show that the designed label recognition filter can successfully suppress the crosstalk.  相似文献   

6.
We propose single-to-dual all-optical wavelength conversion based on stimulated Raman effect on silicon waveguides. Simulation results of non-return-to-zero (NRZ) pseudorandom bit sequence (27–1 code) at 10, 50, and 200-Gbit/s rates of conversion in an ultra-small silicon-on-insulator waveguide are presented. The main goal in the proposed scheme is that the converted signal can be obtained simultaneously inverted, at the 1550 nm channel (down-conversion) and non-inverted, at the 1846 nm channel (up-conversion), for original signal fixed at 1686 nm.  相似文献   

7.
张峰  陈勇  简水生 《光学学报》2007,27(6):87-992
利用半导体光放大器(SOA)的增益饱和特性、自相位调制(SPM)效应和啁啾光纤光栅(CFBG)的滤波和啁啾特性共同作用实现了10 Gbit/s非归零码(NRZ)信号的时钟分量增强。经过该结构的非归零光谱的时钟分量增强后,其时钟数据抑制比提高了12.9 dB。时钟分量增强后的信号经基于受激布里渊效应(SBS)的时钟提取结构后实现了对非归零信号的全光时钟提取。这种新型非归零全光时钟提取结构具有对数据速率及数据格式透明,低抖动,不受码型效应的影响等优点。  相似文献   

8.
光学小波包变换及其滤波器的研究   总被引:2,自引:2,他引:0  
才德  严瑛白  金国藩 《光子学报》2006,35(7):1076-1079
基于对光学小波变换必要条件的分析,提出光学小波包变换的概念.选出虹膜图库的联合最优小波包基,利用最优基的线性组合生成相应的复合光学小波包滤波器.将滤波器用于光电混合虹膜识别系统中对待识别输入进行小波包特征提取预处理,模拟结果不仅证明引入该滤波器可明显提升系统的识别效果,也证明了光学小波包变换提出的意义.  相似文献   

9.
可编程光学击中击不中变换及其在模式识别中的应用   总被引:1,自引:0,他引:1  
袁石夫  张学如 《光学学报》1995,15(2):40-144
提出了一种利用击中击不中变换实现具有边缘噪声的模式的形态识别方法并给出计算模拟结果。利用一个非相干光学相关器,构成了一个实时可编程光学击中击不变处理器。演示了字符识别过程并给出了实验结果。  相似文献   

10.
选择荧光效应强的稀土元素铽,以磺基水杨酸作为第一配体,以聚乙烯醇、聚乙二醇2000等为协配体,对乙醇溶液和水溶液两个体系中形成的配合物荧光进行了研究。试验确定了铽、磺基水杨酸以及聚乙烯醇、聚乙二醇2000为优良协配体的最佳用量。进一步研究发现,表面活性剂的加入对不同配合物的荧光均会产生增强效果,十二烷基磺酸钠效果最好;同时探索了酸度对体系荧光强度的影响。对于获得的铽-磺基水杨酸-聚乙烯醇配合物,其荧光激发波长为342 nm,而荧光发射波长为545 nm,将该配合物以适当比例掺加到农用塑料薄膜中,制备出可以使太阳光的紫外部分转换为作物光合作用需要的绿光的稀土光转换膜。  相似文献   

11.
Abstract

Over the past 30 years, network applications have changed with the advent of innovative services spanning from high-speed broadband access to mobile data communications and to video signal distribution. To support this service evolution, optical transport infrastructures have changed their role. Innovations in optical networking have not only allowed the pure “bandwidth per fiber” increase, but also the realization of highly dependable and easy-to-manage networks. This article analyzes the innovations that have characterized the optical networking solutions from different perspectives, with a specific focus on the advancements introduced by Alcatel-Lucent's research and development laboratories located in Italy. The advancements of optical networking will be explored and discussed through Alcatel-Lucent's optical products to contextualize each innovation with the market evolution.  相似文献   

12.
A high-efficiency optical filter, based on a counter-propagating wavelength converter in ZnTe, is theoretically demonstrated. The filter has extremely narrow bandwidth of 0.5 Å corresponding to pump 0.3 W power and 1 cm length of quasi-phase-matching (QPM) grating, tunable over several nanometers of bandwidth by combination of the grating length and pump power variation. The presented scheme is also a candidate for a wavelength-dependant switch.  相似文献   

13.
王咏胜  付永庆 《光子学报》2014,39(9):1697-1701
一般的轮廓波变换只对信号的低频部分进行分解,却忽略了信号的高频部分,因而丢失了丰富的细节和纹理信息,为了克服这种缺陷,本文利用解析的双树复小波包变换和非抽样方向滤波器组,构造了复轮廓波包变换,并提出一种基于相邻系数阈值分类的复轮廓波包图像去噪算法.新的变换除了具有多分辨率、局部性、多方向性和各向异性的特点外,还具有平移不变性和更丰富的方向分量.仿真试验结果表明,构造的复轮廓波包变换能够有效地抑制伪Gibbs现象,并且保护更多的边缘和纹理等细节,其PSNR值和视觉质量均优于一般的去噪方法.  相似文献   

14.
An optoelectronic implementation of polynomial evaluation has been presented which uses a recirculating inverse perfect shuffle interconnection (IPS). The IPS interconnection is formed by a binary phase grating which permits a high density of interconnection; it can be utilized in a high order of polynomial evaluation processing system.  相似文献   

15.
人工神经网络及其在光谱分析中的应用   总被引:11,自引:2,他引:11  
介绍了人工神经网络的原理及研究进展,对典型神经网络系统作了详细的介绍,对人工神经网络在光谱分析中的应用做了较全面的评述。人工神经网络已成为光谱分析中重要的研究方法之一。  相似文献   

16.
光纤耦合模理论及其在光纤布拉格光栅上的应用   总被引:10,自引:2,他引:10  
将正确的光纤中的正交关系应用于微扰耦合模理论得到了光纤中的微扰耦合模方程;并将其应用于光纤布拉格光栅,得到了一种新耦合模方程。该方程中作为标志性特性的耦合系数与其它理论中的耦合系数都不相同。讨论了方程的解,得到了峰值反射率与布拉格波长、光栅长度之间的简单关系式。用光纤布拉格光栅进行了实验,理论和实验结果符合得很好。  相似文献   

17.
一种新型稀土光转换剂的合成及其与塑料相容性研究   总被引:9,自引:0,他引:9  
用相转移催法合成了长链2-辛基-1, 3-二苯基-1, 3-丙二酮(ODBM)及其Sm的配合物并用IR,EA,UV和1H NMR对化合物进行了表征;Sm配合物粉末及其在PVC,PE中都能在波长650 nm处光致发光;长链的引入使Sm配合物与PVC,PE具有较好的相容性;因此,长链Sm配合物是一种在树脂中相容性好、发光波长与植物光合作用所需的光波长643和660 nm相吻合的光转换剂。  相似文献   

18.
为了实现地质雷达数据精细处理,提高地质雷达数据处理解释的准确度,以授权发明专利《一种地质雷达精细处理方法及系统》为基础,重点研究地质雷达精细处理系统的实现过程。结合软件工程理念,在深入研究地质雷达精细处理系统各模块功能及方法的基础上,设计精细处理算法。应用GPU-CUDA并行处理、快速成像、双线性插值、多种处理方法集成等技术,基于Linux-QT-CUDA的创新编译平台完成地质雷达精细处理软件系统开发。与此同时,该软件系统还实现了地质雷达精细处理成果的即见即所得以及任意圈定异常的显微镜功能。两个不同地区地质雷达野外实测资料试验结果表明,该软件系统不仅稳定、可靠、可交互性好、运行效率高、实现了地质雷达资料的一体化精细处理,而且在突出有效异常、提高地下目标体的识别能力方面取得实效。  相似文献   

19.
针对多传感器数据融合和目标识别的特点,提出了改进的对向传播网络(MCPN),并与Dempster-Shafer(D-S)证据推理相结合,实现了决策层数据融合目标识别.文中利用仿真数据对所提出的网络训练算法和融合结构进行了实验研究.结果表明:改进后的对向传播网络识别性能优于传统的对向传播网络(CPN),融合后的目标识别率较单传感器明显提高.最后,将该方法应用于前视红外(FLIR)和可见光摄像机目标跟踪系统对算法和融合结构进行验证,结果表明文中提出的方法是可行的.  相似文献   

20.
To find a basic principle of optical computed tomography (optical CT), a fundamental study was conducted on the use of scattered light in diffuse random media. We call the scattered light that propagates along the optical axis of the incident light beam near-axis scattered light (NASL). The use of NASL for the imaging through a diffuse medium was proposed and its basic characteristics were analyzed. The existence and measurability of NASL were confirmed in the simulation and measurement. To detect NASL efficiently, a technique called the scattering angle differential technique was developed. In CT imaging with a model phantom, the feasibility and effectiveness of the proposed technique were verified. We found that this technique alone was not sufficient to obtain the cross sectional image of an animal body, therefore a technique called the contact technique was devised to overcome the problems of reflection and refraction at the air-tissue interface. Finally, a prototype system was developed which integrated all the proposed techniques. With this system, we could obtain the CT images of a living mouse, in which the blood-rich organs such as liver and kidneys were clearly recognizable.  相似文献   

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