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	Continuous interior penalty finite element methods for the time-harmonic Maxwell equation with high wave number 期刊论文 OAI收割 ADVANCES IN COMPUTATIONAL MATHEMATICS, 2019, 页码: 27 作者: Lu, Peipei; Wu, Haijun; Xu, Xuejun \| 收藏 \| 浏览/下载：23/0 \| 提交时间：2020/05/24 Time-harmonic Maxwell equation High wave number Continuous interior penalty finite element method Error estimates
	A Robust Multilevel Preconditioner Based on a Domain Decomposition Method for the Helmholtz Equation 期刊论文 OAI收割 JOURNAL OF SCIENTIFIC COMPUTING, 2019, 卷号: 81, 期号: 1, 页码: 291-311 作者: Lu, Peipei; Xu, Xuejun \| 收藏 \| 浏览/下载：57/0 \| 提交时间：2019/10/28 Multilevel method Helmholtz equation High wave number Continuous interior penalty finite element method GMRES method Overlapping domain decomposition method
	Solving Helmholtz equation at high wave numbers in exterior domains 期刊论文 OAI收割 APPLIED MATHEMATICS AND COMPUTATION, 2017, 卷号: 298, 页码: 221-235 作者: Wang, Kun; Wong, Yau Shu; Huang, Jizu \| 收藏 \| 浏览/下载：24/0 \| 提交时间：2018/07/30 Helmholtz equation High wave number Local refinement Polar and spherical coordinates Pollution-free scheme
	A Hybridizable Discontinuous Galerkin Method for the Time-Harmonic Maxwell Equations with High Wave Number 期刊论文 OAI收割 COMPUTATIONAL METHODS IN APPLIED MATHEMATICS, 2016, 卷号: 16, 期号: 3, 页码: 429-445 作者: Feng, Xiaobing; Lu, Peipei; Xu, Xuejun \| 收藏 \| 浏览/下载：22/0 \| 提交时间：2018/07/30 Hybridizable Discontinuous Galerkin Method Time-Harmonic Maxwell Equations High Wave Number Error Estimates
	A ROBUST MULTILEVEL METHOD FOR THE TIME -HARMONIC MAXWELL EQUATION WITH HIGH WAVE NUMBER 期刊论文 OAI收割 SIAM JOURNAL ON SCIENTIFIC COMPUTING, 2016, 卷号: 38, 期号: 2, 页码: A856-A874 作者: Lu, Peipei; Xu, Xuejun \| 收藏 \| 浏览/下载：18/0 \| 提交时间：2018/07/30 multilevel method time-harmonic Maxwell equation high wave number continuous interior penalty finite element method GMRES method local Fourier analysis
	The Research of real time auto-recognition of the moire fringe (EI CONFERENCE) 会议论文 OAI收割 International Symposium on Photoelectronic Detection and Imaging 2011: Advances in Imaging Detectors and Applications, May 24, 2011 - May 26, 2011, Beijing, China Wang M.-J.; Wu Z.-G. 收藏 \| 浏览/下载：19/0 \| 提交时间：2013/03/25 Measuring the movement of raster by the method of moire fringe has the advantage of high sensitivity high resolution and non-contacted measurement. The characteristic of moire fringe is that the image is white alternate with black the angle of the stripes is uniform the width of the stripes is uniform the terminators of the stripes aren't clear. A fast method that can figure out the width and angle of the moire fringe precisely is put forward in this paper. It calculates the angle the stripes firstly. According to the principle of the minimum mean squared error (MMSE) the closer a series of data is the smaller the value of the MMSE will be. The method is described as follows: It takes the image's center as the origin 180 beelines pass through the origin with the same angle interval. it calculates the value of the minimum mean squared error of the 180 beelines and find out the least one among those then the angle of the moire fringe comes out primarily. In order to improving the calculating precision of moire fringe 60 equal angles are divided in the neighborhood of the angle then a precise angle of moire fringe is calculated according to the principle of the MMSE. After getting out the angle of the moire fringe we begin to calculate the width of moire fringe. A line vertical with the moire fringe is drawn and we can get the width of the moire fringe by the vertical line. In order to get over the influence of the noise an effective area with the shape of diamond is selected in the image. The data of area is accumulated and projected according to the direction of moire fringe and a sine curve come out. The width of moire fringe can be obtained by getting the position of the first wave crest the position of the last wave crest and the number of wave crest. Experiments prove that the precision of the method put forward in this paper is enhanced in comparison with the traditional frequency method the precision of width calculation achieves to 99.6% according to the evaluation indicators of width detection error. The computing speed is boosted largely compared with traditional method and it can achieve with 15 ms that satisfying the demand of real time. 2011 SPIE.
	Design and tolerance analysis of compensator for high order aspheric surface testing (EI CONFERENCE) 会议论文 OAI收割 2009 International Conference on Optical Instruments and Technology - Optoelectronic Measurement Technology and Systems, October 19, 2009 - October 22, 2009, Shanghai, China 作者: Chen X.; Liu W.; Chen X.; Chen X. 收藏 \| 浏览/下载：28/0 \| 提交时间：2013/03/25 High accuracy is required in surface testing of 90nm nodal point lithography projecting lens. By comparing various aspheric surface testing methods the structure layout of the compensator is a meniscus positive lens combined with a Plano-convex positive lens. The design results indicate that: primary and high order aberrations are balanced well we adopt Offner null compensator to test the aspheric surface in the point diffraction interferometer at last. In this paper MTF exceeds diffraction limit an Offner compensator is presented on the base of the third order aberration theory to test concave aspheric surface root-mean-square (RMS) of wave front error /167. The F-number of the system can achieve F/1.64. By the analysis of the process of aspheric surface testing with the designed system the optical construction parameters of which is determined by introducing equal-quantities spherical aberration to compensate all orders of aspheric coefficients. The field of view of the system is 0.02 a loosen distribution of the tolerance was presented based on the accuracy of measuring apparatus. 2009 SPIE.
	Integrated optical amplifiers based on rare-earth doped (red) oxide glasses (EI CONFERENCE) 会议论文 OAI收割 International Symposium on Photonic Glass (ISPG 2002), October 14, 2002 - October 17, 2002, Shanghai, China 作者: Chen B.; Chen B. 收藏 \| 浏览/下载：36/0 \| 提交时间：2013/03/25 Oxide glasses have been used since long time to host a number of active compounds first of all rare-earth (RE) ions for lasing. Recently the advantages offered by guided-wave format namely the small size the high pump power density and the larger flexibility in design and fabrication led to the development of fiber lasers and amplifiers based on Er3+-doped glasses. Currently a growing activity is aimed at achieving large optical gain in Er3+-doped planar waveguides having in mind the single-chip realization of integrated optical amplifiers and lasers. The aim of the present paper is to provide a quick overview of this area and to briefly discuss possible future developments.