Photoelectronic Technology Committee Conferences最新文献

{"title":"An enhanced moment matching method to destriping EO-1/Hyperion data","authors":"Y. Bao, C. Yue, Hongyan He","doi":"10.1117/12.2179698","DOIUrl":"https://doi.org/10.1117/12.2179698","url":null,"abstract":"The striping noise can obscure the true radiation information in the images, reduce the accuracy of hyperspectral images, and have serious effect for visual interpretation and further results based on spectral analyses. This paper introduces the principle of moment matching method, emphasizes the analysis of the formative reason for “edge effect”, and then proposes an enhanced method to destripe EO-1/Hyperion data. The method for destriping has been introduced as well in this paper to compare with the moment matching method from both visual effect and quantitative assessment. It shows that the proposed method could achieve the greater effect for destriping EO-1/Hyperion data.","PeriodicalId":225534,"journal":{"name":"Photoelectronic Technology Committee Conferences","volume":"14 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":"125411613","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}

{"title":"Spectroscopic properties of Nd3+/Yb3+ co-doped in lithium aluminum silicate glass for 1.0 μm fiber laser","authors":"Kexuan Han, F. Yu, Yanyan Guo","doi":"10.1117/12.2180267","DOIUrl":"https://doi.org/10.1117/12.2180267","url":null,"abstract":"The Nd3+, Yb3+ singly doped and Nd3+ /Yb3+ co-doped lithium aluminum silicate glasses are fabricated by using a conventional melt quenching technique in air atmosphere, with the molar composition of (60-a-b)SiO2-3Al2O3-20Li2O-12MgO-5CaO-aNd2O3-bYb2O3 (with a=0, 0.25, 0.5, 1 and b=0,2). The Spectroscopic properties of 1.0 μm emission and Luminescence lifetime in Nd3+ /Yb3+ co-doped lithium aluminum silicate glasses are investigated under 808 nm excitation. The Judd–Ofelt theory is used to study the spectroscopic properties of Nd3+ . Meanwhile, the emission cross-section of Yb3+ are obtained by using the reciprocity method. A broad emission band from 950 to 1,100 nm is detected when the Nd3+ /Yb3+ co-doped in lithium aluminum silicate glasses excited by 808 nm LD. The energy transfer process from Nd3+ →Yb3+ co-doped in lithium aluminum silicate glasses is described in this paper.","PeriodicalId":225534,"journal":{"name":"Photoelectronic Technology Committee Conferences","volume":"100 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":"126924004","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}

{"title":"Recent development of infrared tunable filter","authors":"Dafu Liu, Qin-fei Xu, D. Mo","doi":"10.1117/12.2179550","DOIUrl":"https://doi.org/10.1117/12.2179550","url":null,"abstract":"Researchers are engaging on tunable infrared (IR) filters, miniature Fabry-Perot optical devices, to operate IR detector like a spectrometer. This kind of devices was used in astronomical detection field in the 1950s. To meet the miniature, lightweight requirements of the optical detection system, researchers began to make small, lightweight, and cheap tunable IR filters. Nowadays researchers have applied a variety of different structures and the IR filter, and are attempting to integrate them with IR detectors directly. Tunable filter thin film mechanical and thermal properties, and working conditions will affect the tunable filter optical performance. In this article we give two main influencing factors, interface roughness and curvature effect. we also present and discuss the current development of FPF in different groups around the world.","PeriodicalId":225534,"journal":{"name":"Photoelectronic Technology Committee Conferences","volume":"19 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":"116540407","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}

{"title":"Dark-current characteristics of GaN-based UV avalanche photodiodes","authors":"Jin-tong Xu, Chao-wen Chang, Xiang-yang Li","doi":"10.1117/12.2180819","DOIUrl":"https://doi.org/10.1117/12.2180819","url":null,"abstract":"For UV detecting, it needs high ratio of signal to noise, which means high responsibility and low noise. GaN-based avalanche photodiodes can provide a high internal photocurrent gain. In this paper, we report the testing and characterization of GaN based thin film materials, optimization design of device structure, the device etching and passivation technology, and the photoelectric characteristics of the devices. Also, uniformity of the device was obtained. The relationship between dark current and material quality or device processes was the focus of this study. GaN based material with high aluminum components have high density defects. Scanning electron microscope, cathodoluminescence spectra, X-ray double crystal diffraction and transmission spectroscopy testing were employed to evaluate the quality of GaN-based material. It shows that patterned sapphire substrate or thick AlN buffer layer is more effective to get high quality materials. GaN-based materials have larger hole ionization coefficient, so back incident structure were adopted to maximize the hole-derived multiplication course and it was helped to get a smaller multiplication noise. The device with separate absorption and multiplication regions is also prospective to reduce the avalanche noise. According to AlGaN based material characteristics and actual device fabrication, device structure was optimized further. Low physical damage inductively coupled plasma (ICP) etching method was used to etch mesa and wet etching method was employed to treat mesa damage. Silica is passivation material of device mesa. For solar-blind ultraviolet device, it is necessary to adopt a wider bandgap material than AlGaN material. The current-voltage characteristics under reverse bias were measured in darkness and under UV illumination. The distribution of dark current and response of different devices was obtained. In short, for GaN-based UV avalanche photodiode, dark current was related to high density dislocation of thin film materials and device processes, especially the mesa etching and passivation. More and more proofs reveal that the mesa formation course even plays the most important role in generation of dark current.","PeriodicalId":225534,"journal":{"name":"Photoelectronic Technology Committee Conferences","volume":"25 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":"125205382","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}

{"title":"Visual saliency detection based on modeling the spatial Gaussianity","authors":"H. Ju","doi":"10.1117/12.2182055","DOIUrl":"https://doi.org/10.1117/12.2182055","url":null,"abstract":"In this paper, a novel salient object detection method based on modeling the spatial anomalies is presented. The proposed framework is inspired by the biological mechanism that human eyes are sensitive to the unusual and anomalous objects among complex background. It is supposed that a natural image can be seen as a combination of some similar or dissimilar basic patches, and there is a direct relationship between its saliency and anomaly. Some patches share high degree of similarity and have a vast number of quantity. They usually make up the background of an image. On the other hand, some patches present strong rarity and specificity. We name these patches “anomalies”. Generally, anomalous patch is a reflection of the edge or some special colors and textures in an image, and these pattern cannot be well “explained” by their surroundings. Human eyes show great interests in these anomalous patterns, and will automatically pick out the anomalous parts of an image as the salient regions. To better evaluate the anomaly degree of the basic patches and exploit their nonlinear statistical characteristics, a multivariate Gaussian distribution saliency evaluation model is proposed. In this way, objects with anomalous patterns usually appear as the outliers in the Gaussian distribution, and we identify these anomalous objects as salient ones. Experiments are conducted on the well-known MSRA saliency detection dataset. Compared with other recent developed visual saliency detection methods, our method suggests significant advantages.","PeriodicalId":225534,"journal":{"name":"Photoelectronic Technology Committee Conferences","volume":"11 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":"122637681","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}

{"title":"Electroluminescence of cubic boron nitride single crystal flakes with color-zoning","authors":"X. Liu, Shuang Wang, Zhanguo Chen, G. Jia, T. Bian, Lixin Hou, Qi Wang, Nian Liu","doi":"10.1117/12.2180321","DOIUrl":"https://doi.org/10.1117/12.2180321","url":null,"abstract":"The current-voltage (I-V) characteristics and phenomena of electroluminescence of cubic boron nitride (cBN) single crystal flakes with color-zoning under extremely non-uniform electric fields (ENUEFs) induced by needle-plate electrodes were observed. When a cBN flake with sizes of 0.3×0.3×0.1 mm3 was tightly fixed between the tungsten needle and brass plate electrodes in the atmosphere, the I-V relationship exhibited nonlinearity, and peculiar phenomena of electroluminescence with bright blue-violet light appeared at the bias voltage in a range of 700-1200 V. The current-controlled differential negative resistance was synchronously observed. The electroluminescent phenomena were somewhat different for cases of the needle electrode respectively contacting to the amber and transparent zones. The electroluminescent radiations of cBN flakes biased at voltages with a range of 600-1550 V were also investigated in vacuum. In a vacuum chamber, the green emitting phosphor spread around the cBN flake might be excited by the vacuum ultraviolet (VUV) emission from the cBN crystal, and the green fluorescence was observed by naked eyes. The VUV radiation spectrum with a peak wavelength of 149 nm was measured. In the atmosphere, the blue-violet light emission may be the gas discharge resulted from the air ionization induced by the VUV emission from the cBN crystal under the ENUEF, and the ENUEF subsequently keeps the air discharging. The VUV emission from the cBN crystal under the ENUEF can be caused by the original interband transition and the subsequent intraband transfer for electrons, and the final electron-hole direct recombination.","PeriodicalId":225534,"journal":{"name":"Photoelectronic Technology Committee Conferences","volume":"1 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":"131274781","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}

{"title":"A hyperspectral image optimizing method based on sub-pixel MTF analysis","authors":"Yun Wang, Kai Li, Jinqiang Wang, Yajie Zhu","doi":"10.1117/12.2182747","DOIUrl":"https://doi.org/10.1117/12.2182747","url":null,"abstract":"Hyperspectral imaging is used to collect tens or hundreds of images continuously divided across electromagnetic spectrum so that the details under different wavelengths could be represented. A popular hyperspectral imaging methods uses a tunable optical band-pass filter settled in front of the focal plane to acquire images of different wavelengths. In order to alleviate the influence of chromatic aberration in some segments in a hyperspectral series, in this paper, a hyperspectral optimizing method uses sub-pixel MTF to evaluate image blurring quality was provided. This method acquired the edge feature in the target window by means of the line spread function (LSF) to calculate the reliable position of the edge feature, then the evaluation grid in each line was interpolated by the real pixel value based on its relative position to the optimal edge and the sub-pixel MTF was used to analyze the image in frequency domain, by which MTF calculation dimension was increased. The sub-pixel MTF evaluation was reliable, since no image rotation and pixel value estimation was needed, and no artificial information was introduced. With theoretical analysis, the method proposed in this paper is reliable and efficient when evaluation the common images with edges of small tilt angle in real scene. It also provided a direction for the following hyperspectral image blurring evaluation and the real-time focal plane adjustment in real time in related imaging system.","PeriodicalId":225534,"journal":{"name":"Photoelectronic Technology Committee Conferences","volume":"33 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":"132609664","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}

{"title":"Geometric correction method of rotary scanning hyperspectral image in agriculture application","authors":"P. Wan, Guijun Yang, Bo Xu, Haikuan Feng, Haiyang Yu","doi":"10.1117/12.2178351","DOIUrl":"https://doi.org/10.1117/12.2178351","url":null,"abstract":"In order to meet the demand of farmland plot experiments hyperspectral images acquisition, an equipment that incorporating an aerial lift vehicle with hyperspectral imager was proposed. In this manner, high spatial resolution (in millimeter) imageries were collected, which meets the need of spatial resolution on farm experiments, but also improves the efficiency of image acquisition. In allusion to the image circular geometric distortion which produced by telescopic arm rotation, an image rectification method that based on mounted position and orientation system was proposed. Experimental results shows that the image rectification method is effective.","PeriodicalId":225534,"journal":{"name":"Photoelectronic Technology Committee Conferences","volume":"13 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":"132506575","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}

{"title":"A detection method of infrared dim small target under complex cloud background","authors":"Ruo-wang Chen, Chunsheng Hu, Wei-feng Liu, Jian-kang Shi","doi":"10.1117/12.2179509","DOIUrl":"https://doi.org/10.1117/12.2179509","url":null,"abstract":"Based on the analysis of the characteristics of infrared dim small target under complex cloud background, A detection algorithm is proposed for infrared dim small target. Firstly, median filtering algorithm is employed to remove the noise effectively. Secondly, according to the characteristics of the cloud background and targets, a frequency-domain processing method based on Fourier transform and second-order Butterworth high pass filtering is proposed. The cutoff frequency of the filter is adaptively decided by establishing the relationship between the background complexity and the cutoff frequency. Lastly, target detection is achieved by threshold segmentation. Experiments showed that the algorithm can effectively detect infrared dim small target under complex cloud background.","PeriodicalId":225534,"journal":{"name":"Photoelectronic Technology Committee Conferences","volume":"12 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":"131557920","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}

{"title":"A high performance constant fraction discriminator for pulsed laser proximity fuze","authors":"Pingping Yao, Bi-hai Tu, Xiang Wang, Yi Zhang, Ping-jian Zhao","doi":"10.1117/12.2179946","DOIUrl":"https://doi.org/10.1117/12.2179946","url":null,"abstract":"A novel high performance timing discrimination circuit architecture for a pulsed laser proximity fuze based on constant fraction discrimination technique is constructed and tested. A LC resonant circuit is designed to replace the traditional transmission delay-line to accommodate the special requirements of laser proximity fuze for low size, power consumption, weight and cost. The walk error of the improved constant fraction discriminator is analyzed with lots of detailed experiments. The experiment results indicate that the discriminator eliminates the dependency of the echo pulse amplitude from the timing result, the walk error caused by the amplitude variation and the noise variation of the received echo pulse is less than 125ps, when the SNR is more than 20 and the echo pulse is 0.2V to 2.134V (20.12dB dynamic range). The error is less than 100ps when the SNR more than 60. Furthermore, Detection on the whole system integrating the timing discrimination circuit verifies that, the laser repetition frequency can reach 10 KHz, the accuracy of the system with a measurement time of 0.1ms is 1.45cm in the case of a noncooperative target at a measurement range from 2m to 24m at room temperature, which improve greatly the fixed distance precision of pulsed laser proximity fuze.","PeriodicalId":225534,"journal":{"name":"Photoelectronic Technology Committee Conferences","volume":"26 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":"134361172","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}