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浏览/检索结果: 共4条，第1-4条 帮助 限定条件 发表日期：2007     已选(0)清除 条数/页：5101520253035404550556065707580859095100   排序方式：请选择作者升序作者降序题名升序题名降序发表日期升序发表日期降序提交时间升序提交时间降序 Research on the support structure of the primary mirror of large-aperture telescope (EI CONFERENCE) 会议论文 3rd International Symposium on Advanced Optical Manufacturing and Testing Technologies, AOMATT 2007: Large Mirrors and Telescopes, July 8, 2007 - July 12, 2007, Chengdu, China Yang W.; Jingxu Z. 收藏  |  浏览/下载：21/0  |  提交时间：2013/03/25 Large-aperture telescope can be used in surveying battlefield  researching landform  searching object  real-time monitoring  imaging  detecting and identifying spatial targets and so on. A large-aperture telescope for achieving high resolution power is designed to monitor spatial target and image in real time. Real-time monitoring plays an important role in military conflicts. The orbit parameter of object  quantity  geometrical shape parameter and so on can be obtained by detect spatial target. With the development of optical technology  people require larger aperture in optics-electronic (OE) system. By increasing optical aperture  the ability of collecting light and resolution power in the system can be enhanced. But the support structure of the primary mirror of large-aperture telescope will be a very difficult problem. With the increase of primary mirror aperture  the weight of the primary mirror will become larger than before. The root mean square (rms) of the primary mirror is affected by many factors  such as deadweight  deformation of heat  environment and so on. Due to the primary mirror of telescope is an important component of telescope system. By reducing the weight of primary mirror  precision of the system is ensured. During the designing phase  one can consider the supporting project of the primary mirror synthetically and analyze it roundly according to technical requirement of optical system and the effect factors. The final structural design can be reasonable. In an astronomical telescope  the surface of reflector is an important part for collecting dark radiation of celestial bodies. Its surface shape will have an effect on collecting efficiency of telescope radiant energy directly. So the rms must be very high. Optical system of large aperture  small wavelength and small focus can receive maximal light intensity. For ground-based optical astronomical telescope  the design proposed in the paper can satisfy the requirement of the possible minimum atmosphere seeing at astronomical observatory site and exert the use efficiency of the telescope adequately. So the accuracy of the traditional surface of reflector can assure that 90% of all the light energy can be focused on within the angle diameter range of the minimum atmosphere seeing  then 100% of light energy should be focused on the angle diameter range of minimum atmosphere seeing. Because the rms of mirror is very high  precise surface machining and accurate the support of mirror are very important tasks during designing and manufacturing the telescope. In the paper  various support techniques of a large-aperture telescope primary mirror are discussed and a 3.5 meter telescope system at the Starfire Optical Range (SOR) overviewed simply  which was operated by the Directed Energy Directorate of the Air Force Research Laboratory  Kirtland AFB  NM  USA from the ground-based O-E system for the observations of spatial target. We also analyze Theoretical elastic deformation of the Steward Observatory 2.3 meter mirror is analyzed.   Mid-frequency surface error test with a Foucault apparatus (EI CONFERENCE) 会议论文 3rd International Symposium on Advanced Optical Manufacturing and Testing Technologies: Optical Test and Measurement Technology and Equipment, July 8, 2007 - July 12, 2007, Chengdu, China Xuan B.; Li J.; Song S.; Xie J. 收藏  |  浏览/下载：14/0  |  提交时间：2013/03/25 Testing of mid-frequency surface error is of the first importance for fast optics  especially for large aperture aspherics. Foucault test plays a dominant role for surface error inspection before the digital interferometer age  but it seems to have faded out these days because no quantitative results turn out. However  an interferometer with high resolution CCDs is either unavailable or unaccessible in the process of manufacture. As its advantages are realized and recognized for the second time  Foucault test is going back to the stage again. A new theory of calculating the contrast of the shadow pattern of Foucault test is put forward in this paper and some modifications are discussed upon the analyses of the limitation of traditional Foucault apparatus. A paraboloidal mirror was fabricated and tested by the modified Foucault apparatus whose effect has been proved to be great. The methods of controlling mid-frequency error are described in the other paper at this conference- "Multi-mode combine manufacturing technology for large aperture aspheric mirrors"1.   High power VCSEL device with periodic gain active region (EI CONFERENCE) 会议论文 Optoelectronic Materials and Devices II, November 2, 2007 - November 5, 2007, Wuhan, China Ning Y. Q.; Qin L.; Sun Y. F.; Li T.; Cui J. J.; Peng B.; Liu G. Y.; Zhang Y.; Liu Y.; Wang L. J.; Cui D. F.; Xu Z. Y. 收藏  |  浏览/下载：20/0  |  提交时间：2013/03/25 High power vertical cavity surface emitting lasers with large aperture have been fabricated through improving passivation  lateral oxidation and heat dissipation techniques. Different from conventional three quantum well structure  a periodic gain active region with nine quantum wells was incorporated into the VCSEL structure  with which high efficiency and high power operation were expected. The nine quantum wells were divided into three groups with each of them located at the antinodes of the cavity to enhance the coupling between the optical field and the gain region. Large aperture and bottom-emitting configuration was used to improve the beam quality and the heat dissipation. A maximum output power of 1.4W was demonstrated at CW operation for a 400m-diameter device. The lasing wavelength shifted to 995.5nm with a FWHM of 2nm at a current of 4.8A due to the internal heating and the absence of active water cooling. A ring-shape farfield pattern was induced by the non-homogeneous lateral current distribution in large diameter device. The light intensity at the center of the ring increased with increasing current. A symmetric round light spot at the center and single transverse mode operation with a divergence angle of 16 were observed with current beyond 4.8A.   Multi-mode combined manufacturing technology for large aperture aspheric mirrors (EI CONFERENCE) 会议论文 3rd International Symposium on Advanced Optical Manufacturing and Testing Technologies, AOMATT 2007: Large Mirrors and Telescopes, July 8, 2007 - July 12, 2007, Chengdu, China Li J.; Xuan B.; Song S.; Xie J. 收藏  |  浏览/下载：11/0  |  提交时间：2013/03/25 In the field of manufacturing large aperture aspheric mirrors  mid-frequency surface error has been considered to be one of the most important factors for both manufacturing and testing technique. Mid-frequency surface error controlling the polishing process is not conventionally concerned as the same of controlling of low-frequency surface error. In order to solve such a problem  a new method - Multi-mode Combined Manufacturing (MCM) is put forward. MCM technology is useful for the control on all frequency-bands errors of optical surface and is adaptive to fast aspheric mirror especially. Based on classical manufacturing theory  principle analysis of MCM and experiments results are discussed in the paper.