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Central obscuration effects on optical synthetic aperture imaging 会议论文
Conferences of the Photoelectronic Technology Committee of the Chinese Society of Astronautics: Optical Imaging, Remote Sensing, and Laser-Matter Interaction 2013, October 20, 2013 - October 29, 2013, SuZhou, China
Wang X.-W.; Luo X.; Zheng L.-G.; Zhang X.-J.
收藏  |  浏览/下载：26/0  |  提交时间：2015/04/27
Noise analysis and filtering for laser active imaging system 会议论文
2013 2nd International Conference on Sensors, Measurement and lntelligent Materials, ICSMIM 2013, November 16, 2013 - November 17, 2013, Guangzhou, China
Tao S.
收藏  |  浏览/下载：18/0  |  提交时间：2015/04/27
Theoretical research on damage mechanism of ultra fast laser ablation crystal silicon 会议论文
5th International Symposium on Photoelectronic Detection and Imaging, ISPDI 2013, June 25, 2013 - June 27, 2013, Beijing, China
Shao J.; Jin G.; Wang T.
收藏  |  浏览/下载：15/0  |  提交时间：2014/05/15
Morphology and chemical composition analysis on multi-pulsed CO2 laser ablation of HgCdTe crystals 会议论文
5th International Symposium on Photoelectronic Detection and Imaging, ISPDI 2013, June 25, 2013 - June 27, 2013, Beijing, China, June 25, 2013 - June 27, 2013
Tang W.; Guo J.; Shao J.-F.; Wang T.-F.
收藏  |  浏览/下载：11/0  |  提交时间：2014/05/15
Power scaling and beam divergence compression of bottom-emitting vertical-cavity surface-emitting lasers 会议论文
5th International Symposium on Photoelectronic Detection and Imaging, ISPDI 2013, June 25, 2013 - June 27, 2013, Beijing, China
作者:  Zhang X.;  Qin L.
收藏  |  浏览/下载：22/0  |  提交时间：2014/05/15
Nanoscale patterns made by using a 13.5-nm Schwarzschild objective and a laser produced plasma source (EI CONFERENCE) 会议论文
Optical Micro- and Nanometrology IV, April 16, 2012 - April 18, 2012, Brussels, Belgium
Wang Z.; Wang X.; Mu B.; Bai Y.
收藏  |  浏览/下载：29/0  |  提交时间：2013/03/25
Lithium fluoride (LiF) crystal is a very promising candidate as nanometer resolution EUV and soft X-ray detector. Compared with other EUV and soft X-ray detectors  charge coupled device and photographic films  LiF crystal has high resolution  large field of view and wide dynamic range. In this paper  using LiF crystal as EUV detector and a Schwarzschild objective (SO) working at 13.5nm as projection optics  mesh images with 4.2 m  1.2 m and 800 nm line width and pinhole patterns with 1.5m diameter are acquired in projection imaging mode and direct writing mode  respectively. Fluorescence intensity profiles of images show that the resolution of mesh image is 900 nm  and the one of pinhole image is 800 nm. In the experiments  a spherical condense mirror based on normal incidence type is used to eliminate the damage and contamination on the masks (mesh and pinhole) caused by the laser plasma  and the energy density is not decreased compared with that the masks are close to the plasma. The development of the SO  the alignment of the objective and the imaging experiments are also reported. 2012 Copyright Society of Photo-Optical Instrumentation Engineers (SPIE).  
The Research of real time auto-recognition of the moire fringe (EI CONFERENCE) 会议论文
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：15/0  |  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.  
High precision test method for dynamic imaging of space camera (EI CONFERENCE) 会议论文
2010 IEEE International Conference on Advanced Computer Control, ICACC 2010, March 27, 2010 - March 29, 2010, 445 Hoes Lane - P.O.Box 1331, Piscataway, NJ 08855-1331, United States
Zheng G.-F.; Ma S.-F.; Sun J.-G.; Jin L.-X.; Zhang K.
收藏  |  浏览/下载：19/0  |  提交时间：2013/03/25
A test method for dynamic imaging of space TDICCD (Time Delay and Integration Charge Coupled Devices) camera was presented in this paper. The test method adopted the PLL (Phase Locked Loop) technology and CMAC (Cerebella Model Articulation Controller) friction compensation as control strategy. Furthermore  According to this method  a test system for dynamic imaging of space TDICCD camera was designed and implemented. The system simulated the movement of the ground objects relative to the space aerocraft  to validate the capability of image speed match and the dynamic imaging quality of TDICCD camera. The design adopted a precision turntable and a drift turntable to simulate the movement around the earth and the drift motion in different latitude due to the rotation of earth  of the aerocraft. The turntables were drived by permanent magnet torque motor which was powered by PWM (Pulse Width Modulation). The system adopted DSP (Digital Signal Processor) as the control core and reached a very high performance. The experimental results showed that the steady speed error was better than 0.01 % and the instantaneous speed error reached 0.0267%. The precision of the test system designed met the requirement for dynamic imaging of TDICCD camera. 2010 IEEE.  
A high-speed acquisition and processing system of the laser speckle signal on the magnetic fluid (EI CONFERENCE) 会议论文
International Symposium on Photoelectronic Detection and Imaging 2009: Laser Sensing and Imaging, June 17, 2009 - June 19, 2009, Beijing, China
Wan Q.-H.; Jiang Y.; Su S.-C.; Sun Y.; Wu Y.-Z.
收藏  |  浏览/下载：24/0  |  提交时间：2013/03/25
In order to achieve the dynamical detection and real-time analysis of the movement status of the magnetic fluid  according to the difficulties of the detection of the magnetic fluid  established a high-speed acquisition and processing system of laser speckle signal on the magnetic fluid. First of all  the FPGA (EP2C8T144C8N) drived the linear array CCD(TCD1501D) to scan in the corresponding time sequence given by the computer  collected the laser speckle interferometric image in rapid change on the surface of the magnetic fluid  which followed the movement of the magnetic fluid  and the signal collected by CCD was converted into the digital data through the high-speed A/D convertor and stored into the internal buffer FIFO of the FPGA  whose width and depth were designed by the user as required. Then  the FPGA sent the digital signal of the laser speckle interferometric images into the computer through the USB2.0 highspeed differential bus  whose transmission rate can reach 480Mb/s in theory. Finally  the distribution of the laser speckle on the magnetic fluid was messy and random  which carried certain information about the surface of the magnetic fluid  based on the theories of the statistic correlation and the subdivision of images  analysing and processing the laser speckle interferometric images  indirectly got the movement status of the magnetic fluid under the electromagnetic field. The experimental results show that: the High Speed Acquisition and Processing System has the advantage of full-court  non-contact  non-invasive  high-precision and high reliability and so on. The detection resolution of high speed acquisition and processing system is superior to 1m and the sample rate is 3Msps  which basically meets the requirements of the magnetic fluid movement state detection. 2009 SPIE.  

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