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CORC

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Structural design of primary mirror subassembly for space telescope (EI CONFERENCE) 会议论文
2nd International Conference on Mechatronics and Applied Mechanics, ICMAM 2012, December 8, 2012 - December 9, 2012, Taiwan
Xu H.
收藏  |  浏览/下载：43/0  |  提交时间：2013/03/25
In order to design a large aperture primary mirror with the diameter of 1150 mm  the parameters impacting on gravity deformation of the mirror were analyzed and discussed in detail  including material selection  diameter-thickness ratio  the number of the support points  location selection and lightweight structure  etc. A novel space mirror structure system was put forward  and its back was opened and supported by six points on back. The dynamic and static and thermal characteristics were analyzed based on the finite element method. Analysis results showed the surface figure accuracy reached to RMS 14.5nm under the action of gravity load along the optical axis direction and the first-order natural frequency was 214Hz which met to the designed indexes requirements. (2013) Trans Tech Publications  Switzerland.  
Structural design of large aperture rectangular mirror for space telescope (EI CONFERENCE) 会议论文
2nd International Conference on Civil Engineering and Transportation, ICCET 2012, October 27, 2012 - October 28, 2012, Guilin, China
Li Z.
收藏  |  浏览/下载：27/0  |  提交时间：2013/03/25
Structural design of large aperture mirror is one of the key technologies for space telescope development. To meet the requirements of high stiffness  strength and thermal dimensional stability  some factors such as support scheme  materials selection  lightweight design and flexible support design were taken into account. The three supports location of the mirror was determined according to the modal analytical solution. By adjusting the parameters of flexure hinge  influences of gravity  assembly stress and thermal stress on the mirror were reduced obviously. Finite element analysis (FEA) results indicate that the surface accuracy reach to rms10.2nm and 10.8nm under the gravity along optical axis direction and 5C uniform temperature rise respectively  the fundamental frequency of the mirror component is 268Hz. Dynamics test shows that the first order natural frequency is 256Hz  which shows an error less than 5% compared to FEA results. (2013) Trans Tech Publications  Switzerland.  
Design of the real-time autofocusing system for collimator with long focus length and large aperture (EI CONFERENCE) 会议论文
2011 International Academic Conference on Numbers, Intelligence, Manufacturing Technology and Machinery Automation, MAMT 2011, December 24, 2011 - December 25, 2011, Wuhan, China
Li X.; Zhang X.
收藏  |  浏览/下载：34/0  |  提交时间：2013/03/25
Large aperture collimator which has been widely used for calibrating and testing various optical devices plays an essential role in correlative laboratories. As being the basic testing and calibration equipment  the large aperture collimator's accuracy should be much higher than the device under testing in order to ensure the accuracy of the measurement. However  the process of adjusting the collimator is extremely complicated due to the collimator's large aperture and long focal length. So it is difficult to ensure the measurement's quality and easy to cause the system being vulnerable to the surrounding environment. One of the most common problems is defocus. In order to solve the problem above  this issue presents a new type of autocollimator autofocusing system which uses pentaprism instead of using large-aperture plane mirror  semiconductor lasers as light source and CCD sensor as receiver. The system is smaller  lighter  and more convenient when using. The computer simulation shows that the autofocusing system's resolution could reach the accuracy of 40m. If we use the relevant algorithms to execute the sub-pixel scanning  the resolution could reach the accuracy of 10m. It shows that the system could satisfy the required testing precision of testing large aperture optical device.  
Optimization analysis for radial support by finite elements method (EI CONFERENCE) 会议论文
2012 International Conference on Intelligent System and Applied Material, GSAM 2012, January 13, 2012 - January 15, 2012, Taiyuan, Shanxi, China
Li C.; Wang Y.
收藏  |  浏览/下载：15/0  |  提交时间：2013/03/25
Application of carbon fibre reinforced plastic for optical camera structure (EI CONFERENCE) 会议论文
2012 9th IEEE International Conference on Mechatronics and Automation, ICMA 2012, August 5, 2012 - August 8, 2012, Chengdu, China
An Y.; Yao J.-S.
收藏  |  浏览/下载：14/0  |  提交时间：2013/03/25
Optical camera is a high-precision optical instrument  and the optical lens must be always stable under various environments  so the structural materials of optical camera should have good stability and machining performance characteristics. Generally  the weight of the camera increases with the increasing size of optical camera aperture. The application of carbon fibre reinforced plastic(CFRP) in optical camera can help to improve the situation and meet the requirements of large volume and light weight. In this paper  the properties of several kind of materials used in camera structure were compared  the advantages of CFRP used in optical camera were analyzed  the CFRP application profiles of domestic and international were introduced  and the reason of gap was pointed out. There is a conclusion that CFRP will be widely used in the optical camera in China. 2012 IEEE.  
Design of reimaging F/1.0 long-wavelength infrared optical system (EI CONFERENCE) 会议论文
International Symposium on Photoelectronic Detection and Imaging 2011: Advances in Infrared Imaging and Applications, May 24, 2011 - May 24, 2011, Beijing, China
Zhang X.; Liu B.; Jia H.-G.
收藏  |  浏览/下载：27/0  |  提交时间：2013/03/25
A reimaging F/1.0 long-wavelength infrared optical system is proposed. The design has a flexible opto-mechanical layout. The design process is as follows. Firstly  the catadioptric reimaging system consists of two reflecting mirrors and a relay lenses. Two reflecting mirrors make up of the first imaging system and are therefore free of chromatic aberrations  while low dispersion lenses were used in the reimaging system  so the optical system do not need achromatic design for a high image quality. Then  to correct high-order aberrations resulting from large relative aperture  more parameters need to be used with aspheric or diffractive surfaces due to modern optic technology development. Here  aspheric is selected for easily manufacture. Finally  the design is completed with the help of ZEMAX software. The effective focal length of the objective is 120mm and the field of view (FOV) is 4. The simulated final design shows adequate image quality and the modulation transfer function (MTF) is close to diffraction limit. The effect of the surrounding environmental temperature is analyzed using the concept of thermal defocusing  and the thermal compensation is discussed. 2011 Copyright Society of Photo-Optical Instrumentation Engineers (SPIE).  
Laser beacon adaptive optics ophthalmoscope for retinal multilayer imaging (EI CONFERENCE) 会议论文
2nd International Symposium on Bioelectronics and Bioinformatics, ISBB 2011, November 3, 2011 - November 5, 2011, Suzhou, China
Liu R.; Li D.; Xia M.; Kong N.; Qi Y.; Zheng X.; Xuan L.
收藏  |  浏览/下载：17/0  |  提交时间：2013/03/25
Surface modification of SiC mirror by IARE method (EI CONFERENCE) 会议论文
7th International Conference on Thin Film Physics and Applications, September 24, 2010 - September 27, 2010, Shanghai, China
Shen Z.; Gao J.
收藏  |  浏览/下载：16/0  |  提交时间：2013/03/25
A method to prepare high quality SiC coating at low temperature using large aperture E-beam evaporation PVD equipment with ion assistance was developed for the surface modification of SiC mirror for space projects. This method was called Ion Assisted Reactive Evaporation (IARE). The modified SiC coating was prepared using CH4 and Si with Kaufman ion source by IARE at 300C and it had met the requirements of applications. The SiC coating prepared by this method was amorphous. It was dense  homogeneous and easy to be polished. The surface modification of a SiC mirror was carried out using SiC coating by this method and achieved a fine surface modification effect. The surface roughness (rms) of the SiC substrate was reduced to 0.862nm  the scattering coefficient was reduced to 2.79% and the reflectance coated with Ag film was improved simultaneously after the surface modification. The effect of surface modification using SiC coating was close to that of using Si coating. It can be drawn that this technological method to preparation SiC coating for the surface modification of SiC mirror is reasonable and effective. 2011 SPIE.  
Brazing RB-SiC used in large aperture space optical system (EI CONFERENCE) 会议论文
2011 International Conference on Materials and Products Manufacturing Technology, ICMPMT 2011, October 28, 2011 - October 30, 2011, Chengdu, China
Zhang B.; Zhang Z.
收藏  |  浏览/下载：17/0  |  提交时间：2013/03/25
Because of the sic material's superior optical characteristic  machine characteristic and hot characteristic  it becomes currently the space big aperture reflector choose firstly1. For larger aperture sic mirror  it is not economical and safe to make the monolithic body directly 2  3. The SiC mirror brazed assembly with several segments can solve these problems. In this paper  one 600 mm sic plane mirror as demonstration welded with 3 radial segments is roughly grinded to the required figure at first  then the mirror is finely grinded and polished by the technology of CCOS  the mirror figure error is less than 1/20 ( = 632.8nm) in RMS finally. The problems of the preferential removal near braze joint are solved. The methods of reducing the residual stress of mirror are discussed. At last  some measurements and experiments are carried on  and the results conclude that the brazed SiC mirror can meet the requirement of large aperture optical systems. (2011) Trans Tech Publications.  
Reflective foveated optical imaging system based on liquid crystal spatial light modulator (EI CONFERENCE) 会议论文
Optical Design and Testing IV, October 18, 2010 - October 20, 2010, Beijing, China
Peng Q.-Q.; Chang J.; Feng S.-L.; Wang R.-R.
收藏  |  浏览/下载：19/0  |  提交时间：2013/03/25
Based on reflective liquid crystal spatial light modulator (SLM)  a new foveated optical imaging system is proposed. High quality imaging can be realized at any region of interest (ROI) within the field-of-view (FOV) by utilizing the SLM to correct the aberration of different regions dynamically. A reflective cassegrain optical structure is proposed  which is designed  optimized and matched with the reflective SLM to construct a more practical foveated imaging system. This reflective imaging system has a large aperture so that enough light can reach the image plane. It also makes the total length of the system shorter and therefore more practical. We also simulate and analyze the system. This kind of foveated optical imaging system can be applied in wide FOV imaging aspects to reduce bandwidth and optics complexity  and to achieve weight reduction and miniaturization. 2010 Copyright SPIE - The International Society for Optical Engineering.  

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