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Focal plane wave-front sensing algorithm for high-contrast imaging

Science China(physics,Mechanics & astronomy) 2009年第8期52卷 1284-1288页

作者： DOU JiangPei1,2,3,REN DeQing1,2,4,ZHU YongTian1,2 & ZHANG Xi1,2,3 1 National Astronomical Observatories/Nanjing Institute of Astronomical Optics & Technology,Chinese Academy of Sciences,Nanjing 210042,China 2 Key Laboratory of Astronomical Optics & Technology,Nanjing Institute of Astronomical Optics & Technology,Chinese Academy of Sciences,Nanjing 210042,China 3 Graduate university of Chinese Academy of Sciences,Beijing 100049,China 4 physics & astronomy department,california state university northridge,18111 nordhoff street,northridge,california 91330-82.8,usa National Astronomical Observatories/Nanjing Institute of Astronomical Optics & Technology Chinese Academy of Sciences Nanjing 210042 China Key Laboratory of Astronomical Optics & Technology Nanjing Institute of Astronomical Optics & Technology Chinese Academy of Sciences Nanjing 210042 China Graduate university of Chinese Academy of Sciences Beijing 100049 China physics & astronomy department California State University Northridge 18111 Nordhoff Street Northridge California 91330-8268 USA

High-contrast imaging provided by a coronagraph is critical for the direction imaging of the Earth-like planet orbiting its bright parent star.A major limitation for such direct imaging is the speckle noise that is induced from the wave-front error of an optical *** derive an algorithm for the wave-front measurement directly from 3 focal plane *** 3 images are achieved through a deformable mirror to provide specific phases for the optics *** introduce an extra amplitude modulation on one deformable mirror configuration to create an uncorrelated wave-front,which is a critical procedure for wave-front *** simulation shows that the reconstructed wave-front is consistent with the original wave-front theoretically,which indicates that such an algorithm is a promising technique for the wave-front measurement for the high-contrast imaging.

关键词： high-contrast imaging multi-image algorithm speckle nulling technique wave-front sensing

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An iterative wavefront sensing algorithm for high-contrast imaging systems

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Research in astronomy and Astrophysics 2011年第2期11卷 198-204页

作者： Jiang-Pei Dou 1,2,De-Qing Ren 1,2,3 and Yong-Tian Zhu 1,2 1 National Astronomical Observatories/Nanjing Institute of Astronomical Optics & Technology,Chinese Academy of Sciences,Nanjing 210042,China 2 Key Laboratory of Astronomical Optics & Technology,Nanjing Institute of Astronomical Optics & Technology,Chinese Academy of Sciences,Nanjing 210042,China 3 physics & astronomy department,california state university northridge,18111 nordhoff street,northridge,california 91330-82.8,usa National Astronomical Observatories / Nanjing Institute of Astronomical Optics & Technology Chinese Academy of Sciences Nanjing 210042 China Key Laboratory of Astronomical Optics & Technology Nanjing Institute of Astronomical Optics & Technology Chinese Academy of Sciences Nanjing 210042 China physics & astronomy department California State University Northridge 18111 Nordhoff Street Northridge California 91330-8268 USA

Wavefront sensing from multiple focal plane images is a promising technique for high-contrast imaging ***,the wavefront error of an optics system can be properly reconstructed only when it is very *** paper presents an iterative optimization algorithm for the direct measurement of large static wavefront errors from only one focal plane *** first measure the intensity of the pupil image to get the pupil function of the system and acquire the aberrated image on the focal plane with a phase error that will be *** we induce a dynamic phase on the tested pupil function and calculate the associated intensity of the reconstructed image on the focal *** algorithm will then try to minimize the intensity difference between the reconstructed image and the aberrated test image in the focal plane,where the induced phase is a variable of the optimization *** simulation shows that the wavefront of an optical system can theoretically be reconstructed with high precision,which indicates that such an iterative algorithm may be an effective way to perform wavefront sensing for high-contrast imaging systems.

关键词： techniques: image processing -- methods: numerical -- planetarysystems

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Stochastic parallel gradient descent based adaptive optics used for a high contrast imaging coronagraph

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Research in astronomy and Astrophysics 2011年第8期11卷 997-1002页

作者： Bing Dong De-Qing Ren Xi Zhang physics ＆ astronomy department California State University Northridge CA 91330-8268 USA National Astronomical Observatories/Nanjing Institute of Astronomical Optics ＆ Technology Chinese Academy of Sciences Nanjing 210042 China

An adaptive optics （AO） system based on a stochastic parallel gradient descent （SPGD） algorithm is proposed to reduce the speckle noises in the optical system of a stellar coronagraph in order to further improve the contrast. The principle of the SPGD algorithm is described briefly and a metric suitable for point source imaging optimization is given. The feasibility and good performance of the SPGD algorithm is demonstrated by an experimental system featured with a 140-actuator deformable mirror and a Hartrnann-Shark wavefront sensor. Then the SPGD based AO is applied to a liquid crystal array （LCA） based coronagraph to improve the contrast. The LCA can modulate the incoming light to generate a pupil apodization mask of any pattern. A circular stepped pattern is used in our preliminary experiment and the image contrast shows improvement from 10^-3 to 10^-4.5 at an angular distance of 2A/D after being corrected by SPGD based AO.

关键词： instrumentation: adaptive optics -- methods: laboratory -- techniques: image processing coronagraph

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NONLINEAR OPTICS IN QUANTUM WIRES

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中国科学院大学学报 1995年第1期 17-20页

作者： Chen Rei-min(department of physics and astronomy, state university of New York at Buffalo Buffalo, New York 14260-1500, usa and department of physics, Emory university, Atlanta, GA 30322, usa)Lin Duo-liang (department of physics, Hong Kong university of S

ＮＯＮＬＩＮＥＡＲＯＰＴＩＣＳＩＮＱＵＡＮＴＵＭＷＩＲＥＳ￥ＣｈｅｎＲｅｉ－ｍｉｎ（ＤｅｐａｒｔｍｅｎｔｏｆＰｈｙｓｉｃｓａｎｄＡｓｔｒｏｎｏｍｙ，ＳｔａｔｅＵｎｉｖｅｒｓｉｔｙｏｆＮｅｗＹｏｒｋａｔＢｕｆｆａｌｏＢ... 详细信息

ＮＯＮＬＩＮＥＡＲＯＰＴＩＣＳＩＮＱＵＡＮＴＵＭＷＩＲＥＳ￥ＣｈｅｎＲｅｉ－ｍｉｎ（ＤｅｐａｒｔｍｅｎｔｏｆＰｈｙｓｉｃｓａｎｄＡｓｔｒｏｎｏｍｙ，ＳｔａｔｅＵｎｉｖｅｒｓｉｔｙｏｆＮｅｗＹｏｒｋａｔＢｕｆｆａｌｏＢｕｆｆａｌｏ，ＮｅｗＹｏｒｋ１４２...

关键词： optical nonlinearity nonlinear optical susceptibility silicon quantum wires

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Searching for Top Squark at Hadron Colliders

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高能物理与核物理 2002年第Z1期26卷 25-33页

作者： YANG Jin-Min Young Bing-Lin (Institute of Theoretical physics, CAS, Beijing 100080, China)(department of physics and astronomy, Iowa state university, Ames, Iowa 50011, US A) Institute of Theoretical physics CAS Beijing 100080 China Institute of Theoretical physics CAS Beijing 100080 China department of physics and astronomy Iowa State University Ames Iowa 50011 USA

In this talk we briefly summarise our recent study(hep-ph/0007165)on searching fortop squark at hadron *** light top-squark(stop)if produced in hadron colliders in theform of the (?)(?) pair and decaying through the l... 详细信息

关键词：高能物理核物理 QCD Searching for Top Squark at Hadron Colliders pair LHC

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Structure analysis of ^(159)Sm and properties of odd-mass neutron-rich nuclei in mass-160 region

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Science China(physics,Mechanics & astronomy) 2011年第S1期54卷 81-87页

作者： YANG YingChun1 & SUN Yang1,2,3 1 department of physics, Shanghai Jiao Tong university, Shanghai 200240, China 2Institute of Modern physics, Chinese Academy of Sciences, Lanzhou 730000, China 3department of physics and astronomy, university of Tennessee, Knoxville, Tennessee 37996, usa 1. department of physics Shanghai Jiao Tong University Shanghai 200240 China2. Institute of Modern Physics Chinese Academy of Sciences Lanzhou 730000 China3. Department of Physics and Astronomy University of Tennessee Knoxville Tennessee 37996 USA

Recent fission experiment data provide interesting structure information for neutron-rich nuclei in the mass A ～ 160 region. We apply the projected shell model to study the strongly-deformed, neutron-rich Sm isotopes. We perform calculations for rotational bands up to spin I = 20 (29/2) for even-even (odd-neutron) Sm isotopes, and analyze the band structure of low-lying states with quasiparticle excitations. Emphasis is given to rotational bands based on one-quasiparticle (1-qp) configurations in the odd-mass 159Sm. The 159 Sm result is discussed together with those of the even-even isotopes 158,160Sm. New bands in 159Sm based on neutron 1-qp 1/2 and 5/2+ configurations are predicted. Electromagnetic transition probabilities are discussed.

关键词： projected shell model neutron-rich nuclei low-lying excitations isomeric states

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Perturbations of the Yang-Mills field in the universe

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Research in astronomy and Astrophysics 2009年第8期9卷 874-882页

作者： Wen Zhao1,2 1 department of physics, Zhejiang university of Technology, Hangzhou 310014, China W 2 School of physics and astronomy, Cardiff university, Cardiff, CF24 3AA, United Kingdom department of physics Zhejiang University of Technology Hangzhou 310014 China School of physics and astronomy Cardiff University Cardiff CF24 3AA United Kingdom

It has been suggested that the Yang-Mills （YM） field can be a kind of candidate for the inflationary field at high energy scales or dark energy at very low energy scales, which can naturally give the equation of state - 1 〈 ω 〈 0 or ω 〈 - 1. We discuss the zero order and first order Einstein equations and YM field kinetic energy equations of the free YM field models. From the zero order equations, we find that w ＋ 1 ω α^-2, from which it follows that the equation of state of the YM field always goes to - 1, independent of the initial conditions. By solving the first order Einstein equations and the YM field equations, we find that in the YM field inflationary models, the scale-invariant primordial perturbation power spectrum cannot be generated. Therefore, only using this kind of YM field is not enough to account for inflationary sources. However, as a kind of candidate for dark energy, the YM field has the ＇sound speed＇ c^28 = -1/3 〈 0, which makes the perturbation Ф have a damping behavior at large scales. This provides a way to distinguish the YM field dark energy models from other kinds of models.

关键词： cosmology theory- gravitation- methods analytical

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X-ray flares of γ-ray bursts: Quakes of solid quark stars?

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Science China(physics,Mechanics & astronomy) 2009年第2期52卷 315-320页

作者： XU RenXin1 & LIANG EnWei2 1 School of physics and state Key Laboratory of Nuclear physics and Technology, Peking university, Beijing 100871, China 2 department of physics, Guangxi university, Nanning 530004, China 1. School of physics and state Key Laboratory of Nuclear physics and Technology Peking University Beijing 100871 China 2. department of physics Guangxi University Nanning 530004 China

A star-quake model is proposed to understand X-ray flares of both long and short γ-ray bursts (GRBs) in a solid quark star regime. Two kinds of central engines for GRBs are available if pulsar-like stars are actually (solid) quark stars, i.e., the SNE-type GRBs and the SGR-type GRBs. It is found that a quark star could be solidified about 103 to 106 s later after its birth if the critical temperature of phase transi- tion is a few Metga-electron-volts, and then a new source of free energy (i.e., elastic and gravitational ones, rather than rotational or magnetic energy) could be possible to power GRB X-ray flares.

关键词： γ-rays bursts: X-rays neutron stars elementary particles

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X-ray spectra induced by ^(129)Xe^(q+) impacting the metal surface

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Science China(physics,Mechanics & astronomy) 2008年第1期51卷 82-89页

作者： ZHANG XiaoAn 1,2 ,XIAO GuoQing 1 ,YANG ZhiHu 1 ,CHEN XiMeng 3 ,ZHAO YongTao 1 , LI FuLi 4 ,WANG Li 1,2 ,CUI Ying 3 ,ZHANG HongQiang 3 &ZHAN WenLong 1 1Institute of Modern physics,Chinese Academy of Sciences,Lanzhou 730000,China 2department of physics,Xianyang Normal university,Xianyang 712000,China 3department of Modern physics,Lanzhou university,Lanzhou 730000,China 4department of Applied physics,Xi’an Jiaotong university,Xi’an 710049,China 1. Institute of Modern physics Chinese Academy of Sciences Lanzhou 730000 China 2. department of physics Xianyang Normal University Xianyang 712000 China 3. department of Modern physics Lanzhou University Lanzhou 730000 China 4. department of Applied physics Xi’an Jiaotong University Xi’an 710049 China

Using the slow highly charged ions 129 Xe q+ (q=25,26,27;initial kinetic T0≤4.65 keV/a.u.)to impact Au surface,the Au atomic Mαcharacteristic X-ray spectrum is *** result shows that as long as the charge state of projectile is high enough,the heavy atomic characteristic X-ray can be effectively excited even though the incident beam is very weak(nA magnitude),and the X-ray yield per ion is in the order of 10-8and increases with the kinetic energy and potential energy of *** measuring the Au Mα-X-ray spectra,Au atomic N-level lifetime is estimated at about 1.33×10-18s based on Heisenberg uncertainty relation.

关键词： slow highly charged ions characteristic X-ray level lifetime

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Pairwise entanglement and local polarization of Heisenberg model

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Science China(physics,Mechanics & astronomy) 2008年第10期51卷 1515-1522页

作者： XI XiaoQiang1,2, ZHANG Tao3, YUE RuiHong3,4 & LIU WuMing2 1 department of Applied Mathematics and physics, Xi’an Institute of Post and Telecommunications, Xi’an 710061, China 2 Beijing National Laboratory for Condensed Matter physics, Institute of physics, Chinese Academy of Sciences, Beijing 100080, China 3 Institute of Modern physics, Northwest university, Xi’an 710069, China 4 department of physics, Ningbo university, Ningbo 315211, China department of Applied Mathematics and physics Xi’an Institute of Post and Telecommunications Xi’an 710061 China Beijing National Laboratory for Condensed Matter physics Institute of Physics Chinese Academy of Sciences Beijing 100080 China Institute of Modern physics Northwest University Xi’an 710069 China department of physics Ningbo University Ningbo 315211 China

The characteristics of pairwise entanglement and local polarization (LP) are dis-cussed by studying the ground state (states) of the Heisenberg XX model. The re-sults show that: the ground state (states) is (are) composed of the micro states with the minimal polarization (0 for even qubit and 1/2 for odd qubit); LP and the prob-ability of the micro state have an intimate relation, i.e. the stronger the LP, the smaller the probability, and the same LP corresponds to the same probability; the pairwise entanglement of the ground state is the biggest in all eigenvectors. It is found that the pairwise entanglement is decreased by the state degeneracy and the system size. The concurrence approaches a fixed value of about 0.3412 (for odd-qubit chain) or 0.3491 (for even-qubit chain) if the qubit number is large enough.

关键词： Heisenberg XX model local polarization pairwise entanglement

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