中国科学院机构知识库网格系统: 检索

中国科学院机构知识库网格

Chinese Academy of Sciences Institutional Repositories Grid

机构

采集方式

内容类型

发表日期

学科主题

筛选

浏览/检索结果: 共3条，第1-3条

帮助

条数/页：排序方式：
	Design of visible, infrared dual-channel optical system for space target detection (EI CONFERENCE) 会议论文 OAI收割 2011 International Conference on Electronics and Optoelectronics, ICEOE 2011, July 29, 2011 - July 31, 2011, Dalian, China Zhang X. Y. 收藏 \| 浏览/下载：23/0 \| 提交时间：2013/03/25 This paper designs a total of 250mm dual-channel optical system including visible (0.5m0.8m) infrared (3m5m). The main system is a three-reflection system and the primary mirror is designed as the first and the third reflecting surface with different figuring. The cooling infrared detector was choiced in infrared channel and achieves 100% cool shield efficiency of luminescence through the second imaging. The main benefits of this design are the large corrected and unvignetted FOV an easily baffling of stray light small encumbrance and an easy handing. 2011 IEEE.
	Design of dual-FOV refractive/diffractive LWIR optical system (EI CONFERENCE) 会议论文 OAI收割 3rd International Symposium on Advanced Optical Manufacturing and Testing Technologies, AOMATT 2007: Advanced Optical Manufacturing Technologies, July 8, 2007 - July 12, 2007, Chengdu, China 作者: Wang L.-J.; Zhang J.-P.; Wang L.-J.; Zhang X.; Zhang X. 收藏 \| 浏览/下载：33/0 \| 提交时间：2013/03/25 An infrared-optical zoom system using binary element is proposed in this paper. The two main advantages of the zoom system introducing here are: bigger F-number and lower cost. The primary optical properties are: F/#=1 Second Others zoom ratio =1:4 binary element is used to correct the chromatical aberration by taking the advantage of negative dispersion characteristics and the cost of the system is lower than that of conventional ones with Zinc Selenide (Znse) material at the same level. In the binary element is rotational symmetric with one step which is easy to fabricate in order to balance 5th spherical aberration and dual field are 26.6 and 5.6respectively. Wider field of view is used for search and the smaller one is used for imaging details. This system uses un-cooled infrared detector with 320240 pixels and 45m pixel size. The F-number matches the sensitivity range of the detector array. Three aspects are considered during design process to make the system more satisfactory and more achievable. First 5th coma aberration and 5th astigmatic aberration the manner of zoom is accomplished by exchanging tow lenses into the smaller field of view system layout. The lens exchange manner faces the requirement of simple system structure and good image quality in both focal points. It can also make the system more feasible in the alignment process than mechanical-zooming manner and optical-zooming manner high-order asphere surfaces with 2th order to 10 th order are also hired in the system. Asphere surface is useful in compressing the system and improving optical system transmittance. This kind asphere surface is on industrial level featuring low cost and easy to fabricate. It is shown that good image quality can achieved by implementing five Germanium lenses and the transmittance of system is 72%. All aberrations are diffraction-limited both spherical aberration and astigmatic aberration are corrected. When the field of view(FOV) is 26.6 and the focal length is 152mm MTF at Nyquist frequency(11lp/mm) is great than 0.7. The spherical aberration is -0.0073. The coma aberration is 0.0978 and the astigmatic aberration is -0.013. When the field of view(FOV) is 5.6 and the focal length is 38mm MTF at Nyquist frequency is great than 0.8 with spherical aberration -0.0046 the coma aberration 0.055 and astigmatic aberration 0.034.
	Low drive-voltage and high-bandwidth electro-optic modulators based on BaTiO3 thin-film waveguides (EI CONFERENCE) 会议论文 OAI收割 Science and Technology of Dielectrics for Active and Passive Photonic Devices - 210th Electrochemical Society Meeting, October 29, 2006 - November 3, 2006, Cancun, Mexico Sun D. G.; Fu X. H.; Liu Z. F.; Ho S. T.; Wessels B. W. 收藏 \| 浏览/下载：45/0 \| 提交时间：2013/03/25 We investigated electro-optic modulator structures to target low drive voltage high-speed modulation and small device size with c-axis grown BaTiO3/MgO ferro-electric thin films. In this study the calculations are focused on the ideal thin film with a quadratic relation between the half-wave drive voltage V and the interaction length L in the electro-optic modulation case we obtained in previous work. With the quadratic electro-optic modulating relation and the optimal rib waveguide structure of BaTiO3/MgO thin films the frequency-voltage-size performances for 2.5GHz 10GHz 40GHz and 100GHz modulation bandwidths have been obtained under half-wave drive voltages of 0.8V 1.6V 3.0V and 4.8V respectively for the ideal film with r51=730 pm/V at 1550nm wavelength where both the phase velocity matching condition and the conductor induced microwave attenuation are considered. The required device lengths to achieve these four typical values of modulation bandwidth are 3.3 mm 0.8 mm 0.4 mm and 0.2 mm respectively. With the c-axis grown BaTiO3/MgO crystal thin films and the quadratic electro-optic modulating relation an electro-optic coefficient of reff=180 pm/V for the c-axis grown BaTiO3/MgO ferro-electric thin films was measured which is relatively far from the ideal value of r51=560 pm/V. copyright The Electrochemical Society.