Author Affiliations
Abstract
1 Key Laboratory for Quantum Optics and Center for Cold Atom Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China
2 Lab of Quantum Information, University of Science and Technology of China, Hefei 230026, China
3 e-mail: yshzhang@ustc.edu.cn
4 e-mail: yzgui@siom.ac.cn
Quantum beats can be produced in fourth-order interference such as in a Hong–Ou–Mandel (HOM) interferometer by using photons with different frequencies. Here we present theoretically the appearance of interference of quantum beats when the HOM interferometer is combined with a Franson-type interferometer. This combination can make the interference effect of photons with different colors take place not only within the coherence time of downconverted fields but also in the region beyond that. We expect that it can provide a new method in quantum metrology, as it can realize the measurement of time intervals in three scales.
Coherent optical effects Photon statistics Quantum detectors Photonics Research
2015, 3(3): 03000082
Author Affiliations
Abstract
1 Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China
2 Laboratory of Quantum Information, University of Science and Technology of China, Hefei 230026, China
The even-order dispersion cancellation effect based on the frequency anti-correlated photon pairs has attracted much attention in the research of quantum dispersion cancellation in two-photon systems. In this letter, we demonstrate a four-photon quantum interferometry in which we can not only observe the even-order dispersion cancellation effect but also the odd-order cancellation. Importantly, the four-photon scheme can get a much better resolution than the two-photon case and help us get a better understanding of the -interference phenomenon in a four-photon interferometry.
270.1670 Coherent optical effects 270.5290 Photon statistics 270.5570 Quantum detectors Chinese Optics Letters
2014, 12(11): 112701
提出一种用支持向量机(SVM)决策树来对网络流量进行分类的方法，利用SVM决策树在多类分类方面的优势，解决SVM在流量分类中存在的无法识别区域和训练时间较长的问题。对权威流量数据集进行了测试，实验结果表明，SVM决策树在流量分类中比普通的“一对一”和“一对多”SVM方法具有更短的训练时间和更好的分类性能，分类准确率可以达到98.8%。
SVM决策树 流量分类 多类分类 SVM decision tree traffic classification multiclass classification
空军工程大学 电讯工程学院， 陕西 西安710077
针对当前市场上对双路视频监控系统的需求，设计并实现了一种基于FPGA和ARM11的双路远程视频监控系统。该系统通过两个SAA7111A芯片接收解码两路CVBS信号，并在FPGA的控制下将两路信号合成一路传输给ARM11模块。ARM11模块将接收到的视频流打包压缩后发送到IP网上，客户端通过网络连接获取两路监控画面。经过测试表明，该系统性能稳定，能够实现双路视频信号的稳定播放，符合视频产品的设计要求。
视频采集 ARM ARM FPGA FPGA video capture ITU-R BT.656 ITU-R BT.656 SAA7111A SAA7111A
