Photoelectronic Technology Committee Conferences最新文献_第8页

New design of a hybrid plasmonic waveguide 混合等离子体波导的新设计

Photoelectronic Technology Committee Conferences Pub Date : 2015-04-13 DOI: 10.1117/12.2181490

Miao Yi

引用次数: 0

Quenching and temperature dependence of perpendicular magnetic anisotropy of Pt/Co multilayers Pt/Co多层膜垂直磁各向异性的淬火及温度依赖性

Photoelectronic Technology Committee Conferences Pub Date : 2015-04-13 DOI: 10.1117/12.2179671

Yonggang Xu, Xiaolin Zhao, Meng Lv, Guolin Yu, N. Dai, J. Chu

{"title":"Quenching and temperature dependence of perpendicular magnetic anisotropy of Pt/Co multilayers","authors":"Yonggang Xu, Xiaolin Zhao, Meng Lv, Guolin Yu, N. Dai, J. Chu","doi":"10.1117/12.2179671","DOIUrl":"https://doi.org/10.1117/12.2179671","url":null,"abstract":"Magnetic metallic multilayers separated by nonmagnetic metal films are of great importance in magnetoelectronics and spintronics, due to their capacity of giving rise to giant magneto-resistance as well as the electric field control of ferromagnetism. Co/Pt multilayers are one of the typical platforms that own perpendicular magnetic anisotropy which can be tuned in various ways. Since previous investigations focus on the anomalous Hall(transverse) resistivity which characterizes the magnetization of the multilayers, much less attention has been paid to the longitudinal resistivity. In this work, we find that the longitudinal resistivity also gives rich phenomena that need further theoretical treatment. We have grown two Co/Pt multilayer structures that have different spacings between neighboring ferromagnetic layers. The one with smaller spacing shows a superparamagnetic behavior in its Hall resistivity even at a temperature as low as 1.5 K, but the longitudinal resistivity shows a well established hysteresis. The other sample shows square hysteresis in the Hall resistivity at all available temperatures up to 300 K, while the longitudinal resistivity gives no significant signals because they are mostly engulfed in the noises. The corresponding temperature dependence of the coercive field are also different. While the former gives an approximately exponential function of the temperature T, the latter can be divided to two zones, each of which can be characterized by a lnTs dependence, where s is not necessarily an integer. Such distinct features may be deeply related to the microstructures as well as the magnon scattering, which require further investigations.","PeriodicalId":225534,"journal":{"name":"Photoelectronic Technology Committee Conferences","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126738097","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A vehicle photoelectric detection system based on guidance of machine vision 一种基于机器视觉引导的车辆光电检测系统

Photoelectronic Technology Committee Conferences Pub Date : 2015-04-13 DOI: 10.1117/12.2179255

Yawei Wang, Yu Liu, Wei Chen, J. Chen, Jianbing Guo, Lijun Zhou, Haotian Zheng, Xuantao Zhang

引用次数: 0

Photo-and-dark-current-voltage characteristics of normal-incidence GaAs photodetectors with two types of electrode configurations 两种电极结构的正入射砷化镓光电探测器的光-暗电流-电压特性

Photoelectronic Technology Committee Conferences Pub Date : 2015-04-13 DOI: 10.1117/12.2180320

X. Liu, Mingli Li, Zhanguo Chen, G. Jia, T. Bian, Yi Li

{"title":"Photo-and-dark-current-voltage characteristics of normal-incidence GaAs photodetectors with two types of electrode configurations","authors":"X. Liu, Mingli Li, Zhanguo Chen, G. Jia, T. Bian, Yi Li","doi":"10.1117/12.2180320","DOIUrl":"https://doi.org/10.1117/12.2180320","url":null,"abstract":"The characteristics of photo-current-voltage and dark-current-voltage for two-photon-response semi-insulating GaAs photodetectors responding to near-infrared wavelengths of 1.31 μm and 1.55μm are investigated. The semi-insulating GaAs photodetectors were fabricated into hemisphere on whose bottom two types of electrodes were deposited. In experiments, the incident laser was adjusted to travel normally to the photodetector and focus at the center of the bottom so as to improve the nonlinear photo-responsivity markedly. It is observed that the photocurrent dependent on bias exhibits quadratic nonlinearity for both lasers and both electrode configurations, which reflects frequency-doubled absorption responsible for the physical mechanisms of the photodetectors; and the reasonable analysis demonstrates the important role of the electric-field-induced frequency-doubled absorption in two-photon response. Furthermore, it is found that the photocurrent is quite more greater when the electrode positioned at the bottom center of the photodetectors (central electrode for short) is negatively charged than that in the case of it positively charged under the conditions of the identical bias voltage and the same incident optical power; while the dark-current varies in exactly the opposite mode compared to the photocurrent. The aforementioned disparate variations of the photocurrent and the dark-current are well interpreted by the theory of surface band-bending of semi-insulating GaAs, and such variations result in a large ratio of photo-current to dark-current in the case of the central electrode negatively charged. The investigated results also indicate that the optimization of electrode structure is essential to improve the photo-responsivity of the photodetector.","PeriodicalId":225534,"journal":{"name":"Photoelectronic Technology Committee Conferences","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123937179","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Analysis of pixel circuits in CMOS image sensors CMOS图像传感器像素电路分析

Photoelectronic Technology Committee Conferences Pub Date : 2015-04-13 DOI: 10.1117/12.2180432

Zou Mei, Nan Chen, Li-bin Yao

{"title":"Analysis of pixel circuits in CMOS image sensors","authors":"Zou Mei, Nan Chen, Li-bin Yao","doi":"10.1117/12.2180432","DOIUrl":"https://doi.org/10.1117/12.2180432","url":null,"abstract":"CMOS image sensors (CIS) have lower power consumption, lower cost and smaller size than CCD image sensors. However, generally CCDs have higher performance than CIS mainly due to lower noise. The pixel circuit used in CIS is the first part of the signal processing circuit and connected to photodiode directly, so its performance will greatly affect the CIS or even the whole imaging system. To achieve high performance, CMOS image sensors need advanced pixel circuits. There are many pixel circuits used in CIS, such as passive pixel sensor (PPS), 3T and 4T active pixel sensor (APS), capacitive transimpedance amplifier (CTIA), and passive pixel sensor (PPS). At first, the main performance parameters of each pixel structure including the noise, injection efficiency, sensitivity, power consumption, and stability of bias voltage are analyzed. Through the theoretical analysis of those pixel circuits, it is concluded that CTIA pixel circuit has good noise performance, high injection efficiency, stable photodiode bias, and high sensitivity with small integrator capacitor. Furthermore, the APS and CTIA pixel circuits are simulated in a standard 0.18-μm CMOS process and using a n-well/p-sub photodiode by SPICE and the simulation result confirms the theoretical analysis result. It shows the possibility that CMOS image sensors can be extended to a wide range of applications requiring high performance.","PeriodicalId":225534,"journal":{"name":"Photoelectronic Technology Committee Conferences","volume":"47 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122856381","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effect of residual gas on cathode photoelectric emission life in generation III L-L-L tube 残余气体对第三代L-L-L管阴极光电发射寿命的影响

Photoelectronic Technology Committee Conferences Pub Date : 2015-04-13 DOI: 10.1117/12.2087260

Jiangtao Xu, Xiaojun Yang, Chang Chen, Ke Xu, Beibei Liu, Min Li, Honglin Shi

引用次数: 0

Terahertz digital holography image processing based on MAP algorithm 基于MAP算法的太赫兹数字全息图像处理

Photoelectronic Technology Committee Conferences Pub Date : 2015-04-13 DOI: 10.1117/12.2180056

Guang-hao Chen, Qi Li

{"title":"Terahertz digital holography image processing based on MAP algorithm","authors":"Guang-hao Chen, Qi Li","doi":"10.1117/12.2180056","DOIUrl":"https://doi.org/10.1117/12.2180056","url":null,"abstract":"Terahertz digital holography combines the terahertz technology and digital holography technology at present, fully exploits the advantages in both of them. Unfortunately, the quality of terahertz digital holography reconstruction images is gravely harmed by speckle noise which hinders the popularization of this technology. In this paper, the maximum a posterior estimation (MAP) filter is harnessed for the restoration of the digital reconstruction images. The filtering results are compared with images filtered by Wiener Filter and conventional frequency-domain filters from both subjective and objective perspectives. As for objective assessment, we adopted speckle index (SPKI) and edge preserving index (EPI) to quantitate the quality of images. In this paper, Canny edge detector is also used to outline the target in original and reconstruction images, which then act as an important role in the evaluation of filter performance. All the analysis indicate that maximum a posterior estimation filtering algorithm performs superiorly compared with the other two competitors in this paper and has enhanced the terahertz digital holography reconstruction images to a certain degree, allowing for a more accurate boundary identification.","PeriodicalId":225534,"journal":{"name":"Photoelectronic Technology Committee Conferences","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123654190","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Automatic target locating system through cooperative dual-field imaging 双场协同成像自动目标定位系统

Photoelectronic Technology Committee Conferences Pub Date : 2015-04-13 DOI: 10.1117/12.2182248

Kun Huang, Yuqing He, Boyan Hou, Shan Wei, Siyuan Wang

引用次数: 1

Integrated multi-channel receiver for a pulsed time-of-flight laser radar 用于脉冲飞行时间激光雷达的集成多通道接收机

Photoelectronic Technology Committee Conferences Pub Date : 2015-04-13 DOI: 10.1117/12.2178459

Yan Jiang, Ru-qing Liu, Jing-guo Zhu

引用次数: 4

Backscattering metal gratings in QWIPs to increase the long wavelength infrared light absorption qwip中后向散射金属光栅增加长波红外光吸收

Photoelectronic Technology Committee Conferences Pub Date : 2015-04-13 DOI: 10.1117/12.2182255

Y. Liao, Yun Xu, Guofeng Song

{"title":"Backscattering metal gratings in QWIPs to increase the long wavelength infrared light absorption","authors":"Y. Liao, Yun Xu, Guofeng Song","doi":"10.1117/12.2182255","DOIUrl":"https://doi.org/10.1117/12.2182255","url":null,"abstract":"Nowadays, traditional infrared detectors such as MCT infrared photo detectors performance nearly reached their detect theory limits. As lead to an increased interest in detectors such as QWIPs, T2SL, QCD and so on. Due to the low cost, high integration level and high performance, QWIPs is a mainstream infrared photo detector in the areas of military, medicine industries. The problem blocked the QWIPs industry development is the low quantum efficiency because of the polarization dependence of the incident light. As decided by the absorption mechanism, the QWIPs cannot absorb the normal incident infrared light. Various methods is developed to couple the normal incident light to the QWIPs. The introduction of metal gratings proved to be efficient to improve the absorption of the normal incident light which can introduce a SPPs coupling on the interface of the gratings and the QWIPs. But in the method used before usually are transmission gratings on the surface of the QWIPs devices. A kind of backscattering metal grating patterns is designed and simulated in our work to get a higher performance. It is nearly 4 times of the coupling efficiency than the transmission gratings in simulation. We also discuss some grating parameters such as grating thickness and cycle duties for their effects on the coupling efficiency and optimize these parameters to reach a highest performance. The simulation results show a new promising structure use in the QWIPs especially in the dual-band QWIPs to enhance the absorption of the long wavelength infrared light.","PeriodicalId":225534,"journal":{"name":"Photoelectronic Technology Committee Conferences","volume":"78 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124865734","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1