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	Design and fabrication of imaging optical systems with freeform surfaces (EI CONFERENCE) 会议论文 OAI收割 Current Developments in Lens Design and Optical Engineering XIII, August 13, 2012 - August 15, 2012, San Diego, CA, United states 作者: Zhang F.; Wang L.; Wang L.; Wang L.; He X. 收藏 \| 浏览/下载：33/0 \| 提交时间：2013/03/25 Freeform surfaces provide more degrees of freedom for design of optical systems and enhance the ability of compensation and correction aberrations. Freeform surfaces are of advantage to balance the unsymmetrical aberrations especially for the wide-field off-axis optical systems. This paper focus on an off-axis reflective optical system which focal length is 550mm F# is 6.5 and field of view (FOV) is 76. The system adopts some freeform surfaces. We discuss the problems we noticed in processes of design manufacture measurement and alignment and the solutions. At last the periodical research result and the expected performance are given. 2012 SPIE.
	Application of adaptive UKF in initial alignment of MINS/GPS integrated navigation system (EI CONFERENCE) 会议论文 OAI收割 2010 3rd International Conference on Advanced Computer Theory and Engineering, ICACTE 2010, August 20, 2010 - August 22, 2010, Chengdu, China 作者: Gao Q. 收藏 \| 浏览/下载：32/0 \| 提交时间：2013/03/25 In order to overcome the shortcomings of standard unscented Kalman filter (UKF) which are obviously influenced by the error of initial value and the model error of system adaptive UKF which is based on the adaptive principle is applied in initial alignment of the MINS/GPS integrated navigation system. Coarse alignment cannot be done by micro inertial measurement unit (MIMU) itself because of its low precision the method of using magnetometer to assist it with coarse alignment is presented. Simulation results show that the adaptive UKF can overcome the influences of initial values error and inaccurate system model and improve the convergence speed and alignment accuracy effectively. 2010 IEEE.
	Modulation transfer function measurement technique for image sensor arrays (EI CONFERENCE) 会议论文 OAI收割 6th International Symposium on Precision Engineering Measurements and Instrumentation, August 8, 2010 - August 11, 2010, Hangzhou, China 作者: Jiang H. 收藏 \| 浏览/下载：22/0 \| 提交时间：2013/03/25 A new technique is demonstrated for measurement of modulation transfer function (MTF) on image sensor arrays. Fourier analysis of a low frequency bar target pattern is used to extract MTF at odd harmonics of a target pattern frequency up to and beyond Nyquist. The technique is particularly useful for linear image arrays (either conventional linescan or time-delay-integration devices) where conventional slanted-edge technique is not always applicable. The technique is well suited to simple implementation and can provide live presentation of the MTF curve which helps to ensure optimal alignment conditions are achieved. Detailed analysis of the technique and demonstration of experimental results are presented. 2010 SPIE.
	Design and fabrication of CGH for aspheric surface testing and its experimental comparison with null lens (EI CONFERENCE) 会议论文 OAI收割 5th International Symposium on Advanced Optical Manufacturing and Testing Technologies: Optical Test and Measurement Technology and Equipment, April 26, 2010 - April 29, 2010, Dalian, China 作者: Zhao J.; Zhang X.; Zhang X.; Zhang X.; Li F. 收藏 \| 浏览/下载：34/0 \| 提交时间：2013/03/25 Computer-generated hologram (CGH) is an effective way to compensate wavefront in null test of aspheric surfaces and freeform surfaces. Our strategies of CGH design and fabrication for optical testing are presented and an experiment demonstrating the compensation results of CGH and null lens is also reported. In order to design complex CGH software was developed with which we can design a CGH including three sections: main section for compensating wavefront in null test alignment section for adjusting the relative position between CGH and interferometer and fiducial section for projecting fiducial marks around the optics under test. The design result is represented in GDS II format file which could drive a laser-direct-writer- machine to fabricate a photomask. Then a 1:1 replication process is applied to duplicate the patterns from photomask to a parallel optical substrate whose surface is error better than /60 rms. Finally an off-axis aspheric surface was tested with CGH and null lens respectively. The test result with CGH (0.019rms) is almost the same as the result with null lens (0.020 rms). This experiment also demonstrated that fiducial marks projected by CGH can be used to guide the alignment of the optics and measurement of its off-axis distance. 2010 Copyright SPIE - The International Society for Optical Engineering.
	Alignment of off-axis asphere and compensator with four poles (EI CONFERENCE) 会议论文 OAI收割 4th International Symposium on Advanced Optical Manufacturing and Testing Technologies: Optical Test and Measurement Technology and Equipment, November 19, 2008 - November 21, 2008, Chengdu, China 作者: Li J.; Chen Y.; Li J.; Li J.; Wang P. 收藏 \| 浏览/下载：58/0 \| 提交时间：2013/03/25 Aspheres are utilized widely thanks to the development of optical design manufacture and testing. Compensators are usually necessary when aspheres are under test. The alignment of aspheres and their compensators is a risk because it's tough to check whether the compensators work in right way. A new method of alignment with four poles is put forward in this paper. Optical interval error can be tight while it is quite important due to direct influence on central curvature conic constant and high order coefficients of aspherical surface. A modified on-axis Foucault apparatus is set up since it makes the optical axis visible and helps to control the error of off-axis amount. Some small holes are drilled in the metallic cell of the compensator so that the ends of poles can be stably relied on in order to increase operational repeatability. The method has been carried out practically and it matches the measurement result given by a set of theodolites. 2009 SPIE.
	Research on 10.6 m laser beam monitoring in CO2 laser processing system (EI CONFERENCE) 会议论文 OAI收割 Infrared Materials, Devices, and Applications, November 12, 2007 - November 15, 2007, Beijing, China 作者: Gao Y.; Shao S. 收藏 \| 浏览/下载：25/0 \| 提交时间：2013/03/25 It is a key point of CO2 laser beam monitoring in the CO 2 laser processing system to achieve alignment between CO2 laser and PL (pointing and launching) system. By monitoring the angle offset of CO2 laser beam the compensation can be gotten witch is given to fast-steering mirror to rectify the direction of laser beam. But the normal photoelectric detector can not get the laser signal because of CO2 laser's high energy and long wavelength. Its wavelength is 10.6m and its power can reach kW level. Consequently it is difficult to detect the high-energy 10.6m laser beam directly. So we monitored the output mirror of laser resonator superseded the laser beam indirectly. The laser beam monitoring system could be designed based on CCD laser auto-collimation angular measurement principle and image processing method. In this paper application of CCD laser auto-collimation angular measurement principle and image processing method for CO2 laser beam monitoring system is introduced particularly After design fabrication and alignment the monitoring system can be used for experimental study that including angular measurement accuracy and angle offset measurement of CO2 laser beam. Angle offset range and angle variation rule of CO2 laser beam is also can be acquired for further research.