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Performance of a Vertical 4H-SiC Photoconductive Switch With AZO Transparent Conductive Window and Silver Mirror Reflector 期刊论文  OAI收割
IEEE TRANSACTIONS ON ELECTRON DEVICES, 2018, 卷号: 65, 期号: 5, 页码: 2047, 2051
作者:  
Cao, Penghui;  Huang, Wei;  Guo, Hui;  Zhang, Yuming
  |  收藏  |  浏览/下载:46/0  |  提交时间:2018/12/28
Rapid fabrication of a lightweight 2m reaction-bonded SiC aspherical mirror 期刊论文  OAI收割
Results in Physics, 2018, 卷号: 10, 页码: 903-912
作者:  
Li, L. X.;  Liu, Z. Y.;  Xue, D. L.;  Deng, W. J.;  Li, R. G.
  |  收藏  |  浏览/下载:22/0  |  提交时间:2019/09/17
Technology on fabrication of precise SiC aspherical mirror (EI CONFERENCE) 会议论文  OAI收割
2011 International Conference on Materials and Products Manufacturing Technology, ICMPMT 2011, October 28, 2011 - October 30, 2011, Chengdu, China
Zhang Z.
收藏  |  浏览/下载:31/0  |  提交时间:2013/03/25
This paper represents a technique to produce the large size optical aspherical mirror by using reaction-bonded silicon carbide to meet the material requirements of the space used mirrors  based on the characters comparison of all types mirror material. Techniques are described in this paper  including the bonding procedure of silicon carbide to form a mirror shape  the CCOM technology for aspheric grinding  polishing on a home-developed tool -FSGJ-2  and the aspheric profilometry. A specialized Offner Null lens is also developed to measure the aspherical mirror with laser interferometer. With the technology depicted in the paper  a 502mm 298 mm off-axis SiC aspherical mirror is successfully made with a surface accuracy better than 1/50rms  the final result meets the design requirement. (2011) Trans Tech Publications.  
Design and test of pointing mirror assembly for spaceborne remote sensing camera (EI CONFERENCE) 会议论文  OAI收割
2011 International Conference on Electronics, Communications and Control, ICECC 2011, September 9, 2011 - September 11, 2011, Ningbo, China
作者:  
Chen W.
收藏  |  浏览/下载:42/0  |  提交时间:2013/03/25
In order to ensure the surface figure of the pointing mirror (460mm long  290mm wide) in spaceborne remote sensing camera  Silicon Carbide was selected as the mirror material. The form of composite triangular and rectangular and the combination of open and closed back was explored in the lightweight design. A new kinematic mount and flexible structure in axis is used to hold the mirror around the lateral surface. The structure can minimize distortions induced by coefficient of thermal expansion mismatch among the materials. This eliminates the bending of the integral mount under the weight of the mirror. Optical performance of the mirror was analyzed under gravity load and temperature load using finite element method. Predicted surface figure error based on the removal of bias  tilt and power was calculated using an in-house Matlab script for mirrors. The pointing mirror assembly was tested using open loop servo control. And the surface figure was checked using interferometer. Surface figure accuracy is better than 1/30 ( 632.8nm  rms). The results show that the kinematic mount induces minimal figure error on the optical surface. 2011 IEEE.  
Manufacture of 1.2m reaction bonded silicon carbide mirror blank CFID (EI CONFERENCE) 会议论文  OAI收割
5th International Symposium on Advanced Optical Manufacturing and Testing Technologies: Large Mirrors and Telescopes, April 26, 2010 - April 29, 2010, Dalian, China
作者:  
Zhang G.;  Zhang G.;  Zhang G.
收藏  |  浏览/下载:37/0  |  提交时间:2013/03/25
Silicon carbide (SiC) is a new type candidate material for large-scale lightweight space mirror. Its low thermal distortion  high stiffness  fine optical quality and dimensional stability  make SiC an ideal material for large space born telescope. Since ten years Changchun institute optics  fine mechanics and physics (CIOMP) has developed reaction bonded SiC (RB-SiC) technology for space application  and can fabricate RB-SiC mirror with scale less than 1.0 meter for telescope. The green body is prepared with gel-casting method which is an attractive new ceramic forming process for making high-quality  complex-shaped ceramic parts. And then unmolding  drying  binder burning out  reacting bonded  the RB-SiC can be obtained. But with the development of space-born or ground telescope  the scale of primary mirror has exceeded 1.0 meter. So CIOMP has developed an assembly technique which called novel reaction-formed joint technology for larger RB-SiC mirror blank. The steps include joining of green bodies with mixture comprised of SiC particles and phenolic resin etc  firing  machining and sintering. Joining the 1.2 meter RB-SiC mirror blank by the novel reaction-formed joint technology. And testing the welding layer's performance  the results show that the thickness of 54-77m  the microstructure and thermal property can be comparable to the substrate and the mechanical property are excellent in bending strength of 307MPa. 2010 Copyright SPIE - The International Society for Optical Engineering.  
Fabrication technique of large-scale lightweight SiC space mirror (EI CONFERENCE) 会议论文  OAI收割
3rd International Symposium on Advanced Optical Manufacturing and Testing Technologies, AOMATT 2007: Large Mirrors and Telescopes, July 8, 2007 - July 12, 2007, Chengdu, China
作者:  
Zhang G.;  Zhang G.;  Zhang G.
收藏  |  浏览/下载:30/0  |  提交时间:2013/03/25
Silicon carbide (SiC) is a new type candidate material for large-scale lightweight space mirror. Its low thermal distortion  high stiffness  high optical quality  and its dimensional stability are better than other traditional optical substrate materials such as ULE  Zerodure  Beryllium (Be) and so on. In this paper  the lightweight silicon carbide space mirror blank was fabricated by reaction sintering. As a space born mirror material  silicon carbide must be an optical grade ceramic. So we prepared the silicon carbide green body with gel-casting method. Then some carbon materials were supplemented into the green body which will bring reaction-sintering with silicon in a vacuum furnace during 1500-1600C  ultimately the reaction bonded silicon carbide was made. The diameter of SiC space mirror blank we have made is 680mm. If expanding the size of the vacuum furnace  bigger mirror blank can be obtained. The test results show that the mechanical and thermal properties of RB-SiC are excellent with bending strength of 350MPa  fracture toughness of 4.1 MPa·m1/2 and coefficient of thermal expansion(CET) of 2.6710-6/K. The surface roughness(RMS) could be better than 3nm.