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	Femtosecond electron pulse compression by using the time focusing technique in ultrafast electron diffraction 期刊论文 OAI收割 chinese physics b, 2011, 卷号: 20, 期号: 11, 页码: 114102 作者: Wen Wen-Long; Lei Xiao-Hong; Hu Xin; Xu Xiang-Yan; Wang Jun-Feng 收藏 \| 浏览/下载：39/0 \| 提交时间：2012/06/29 time focusing technique temporal pulse compressing time-dependent electric field Monte-Carlo method
	Autofocusing technique based on image processing for remote-sensing camera (EI CONFERENCE) 会议论文 OAI收割 International Symposium on Photoelectronic Detection and Imaging 2007 - Image Processing, September 9, 2007 - September 12, 2007, Beijing, China 作者: Wang X.; Xu S.-Y.; Wang X.; Wang X. 收藏 \| 浏览/下载：22/0 \| 提交时间：2013/03/25 The key to the auto-focusing technique based on image processing is the selection of focus measure reflecting image definition. Usually the measures derived are on the premise of the images acquired with the same scene. As for the remote-sensing camera working in linear CCD push-broom imaging mode the premise doesn't exist because the scenes shot are different at any moment which brings about difficulties to the selection of the focus measure. To evaluate the image definition the focus measure based on blur estimation for rough adjustment is proposed to estimate the focused position by only two different lens positions which greatly saves the auto-focusing time. Another evaluation function based on edge sharpness is developed to find best imaging position in the narrow range. Simulations show that the combination of the two measures has the advantages of rapid reaction and high accuracy.
	Key techniques of laser direct writing patterns on spherical substrate (EI CONFERENCE) 会议论文 OAI收割 3rd International Symposium on Advanced Optical Manufacturing and Testing Technologies, AOMATT 2007: Design, Manufacturing, and Testing of Micro- and Nano-Optical Devices and Systems, July 8, 2007 - July 12, 2007, Chengdu, China 作者: Zhao J.-L.; Feng X.-G. 收藏 \| 浏览/下载：24/0 \| 提交时间：2013/03/25 Comparing with the writing method of plane pattern spherical pattern' has some remarkable different on several points. Firstly it is difficult to spin-coated a uniform photoresist film on a spherical substrate especially the ratio of spherical radius to caliber is smaller and the spin-coated way must match the ratio of spherical radius to caliber. Secondly if the sphere couldn't be regarded as a plane a so-called concentric optical scan movement way must be applied for the generation of spherical pattern because the reflex of substrate will affect the quantity of illumination. Commonly an alignment technique is indispensable with pattern generation of spherical surface by the concentric optical scan in order to ensure the orthogonal intersection of focusing laser beam and writing surface. Thirdly a uniform velocity control must be considered for the laser direct writing method on a spherical substrate. Otherwise the exposure time of photoresist will be different and the line widths of pattern will be also different at different areas. Fourthly commonly because the errors of concentric machine and substrate surface shape are bigger so focusing servo-control technique is also needful for writing a pattern on a spherical substrate. Focusing servo-control may keep the focal spot on the spherical surface by a focus detection and control system in the course of writing pattern. Using these techniques we fabricated a line width of 7m and a period of 600m isometric mesh on the concave of a spherical substrate.
	Design of video auto focusing based on image processing (EI CONFERENCE) 会议论文 OAI收割 ICO20: Optical Information Processing, August 21, 2005 - August 26, 2005, Changchun, China Meng B.; Zhu M.; Cai C.-J. 收藏 \| 浏览/下载：21/0 \| 提交时间：2013/03/25 In order to realize the auto focusing technique based on digital image processing a video image processing system is designed by using high-performance digital signal processor TMS320VC5509 as the core field programmable gate array FPGA for preprocessing of image. At the same time it is proposed to use vector norm sum of image gray gradient as evaluation functions of digital image. It has the characteristics of good unbiasedness powerful unimodality etc. and can be applied to evaluation of defocusing. The hardware composition of the theory behind the auto focusing system and the application of the evaluation function are discussed in details.