中国科学院机构知识库网格系统: 检索

Study on sensing properties of a temperature-independent high pressure sensor base on tapered FBG (EI CONFERENCE) 会议论文 OAI收割
International Symposium on Photonics and Optoelectronics, SOPO 2010, June 19, 2010 - June 21, 2010, Chengdu, China
作者: Liu Y.; Zhang Y.; Zhang X.; Zhang X.; Zhang X.

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The sensing properties with strain and temperature of tapered FBG had been researched both theoretically and experimentally. Based on tapered FBG and thin-wall strain cylinder structure a novel temperature-independent high pressure sensor was fabricated and investigated. The tapered FBG performed as a chirped grating whose bandwidth and reflection power broadened and increased when the pressure applied on it. Moreover the bandwidth and the reflection power were temperature-independent. So the value of the strain can be obtained by detecting the reflection power. This method effectively solved the cross-sensitivity problem. The experiment results indicated that this sensor provided a measurement range of 040MPa with a sensitivity of 0.04w/MPa low cost and good application prospect. 2010 IEEE.

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.

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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.

The synthesis and field emission property of carbon nanotubes on carbon fibers substrate (EI CONFERENCE) 会议论文 OAI收割
Technical Digest of the 20th International Vacuum Nanoelectronics Conference, IVNC 07, July 8, 2008 - July 12, 2008, Chicago, IL, United states
Leyong Z.; Weibiao W.; Jingqiu L.; Yuxue X.; Da L.; Song C.; Haifeng Z.

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Using ferrocene as catalyst precursor C2H2 as carbon source carbon nanotubes (CNTs) with uniform density were synthesized on carbon fibers substrate by floating catalyst method. The morphology and microstructure were characterized by field emission scanning electron microscope (FESEM) and high-resolution transmission electron microscopy (HRTEM). The observation showed that the length of CNTs is about 2 m the average space between adjacent CNTs is about 300 nm and the diameter of CNT is about 45 nm. The less dense "short and stubby" aligned CNTs films should have good electron field emission characteristics. The results of field emission showed that the emission current of CNTs/carbon fibers was 5 A at the field of 2.5 V/m and the emission current can be 280 A with a field of 7 V/m (the specimen area is 0.25 cm2 and the distance between cathode and anode is 200 m). The calculation based on the F-N plot indicated that the field enhancement factor of CNTs tip is 499122. Using the conductivity and chemical stability of carbon fibers and the uniform and sparse density distribution of CNTs on carbon fibers substrate the tip predominance of carbon nanotubes can be exerted and simultaneously the effect of screening effects between adjacent carbon nanotubes on the field emission performance can also be effectively decreased. The CNTs synthesized on carbon fibers substrate has many predominances for the fabrication of cold cathode devices. For example using the removability of carbon fibers the cathode of CNTs/carbon fibers can be arbitrarily moved enlaced or combined to form different patterns and the cathode of CNTs/carbon fibers can be also fabricated in large size. Therefore CNTs/carbon fibers may have potential application in field emission displays.

Key techniques of laser direct writing patterns on spherical substrate (EI CONFERENCE) 会议论文 OAI收割
3rd International Symposium on Advanced Optical Manufacturing and Testing Technologies, AOMATT 2007: Design, Manufacturing, and Testing of Micro- and Nano-Optical Devices and Systems, July 8, 2007 - July 12, 2007, Chengdu, China
作者: Zhao J.-L.; Feng X.-G.

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Comparing with the writing method of plane pattern spherical pattern' has some remarkable different on several points. Firstly it is difficult to spin-coated a uniform photoresist film on a spherical substrate especially the ratio of spherical radius to caliber is smaller and the spin-coated way must match the ratio of spherical radius to caliber. Secondly if the sphere couldn't be regarded as a plane a so-called concentric optical scan movement way must be applied for the generation of spherical pattern because the reflex of substrate will affect the quantity of illumination. Commonly an alignment technique is indispensable with pattern generation of spherical surface by the concentric optical scan in order to ensure the orthogonal intersection of focusing laser beam and writing surface. Thirdly a uniform velocity control must be considered for the laser direct writing method on a spherical substrate. Otherwise the exposure time of photoresist will be different and the line widths of pattern will be also different at different areas. Fourthly commonly because the errors of concentric machine and substrate surface shape are bigger so focusing servo-control technique is also needful for writing a pattern on a spherical substrate. Focusing servo-control may keep the focal spot on the spherical surface by a focus detection and control system in the course of writing pattern. Using these techniques we fabricated a line width of 7m and a period of 600m isometric mesh on the concave of a spherical substrate.

Effects of fabricated error on transmission performance of double screens cross loop slot FSS configuration (EI CONFERENCE) 会议论文 OAI收割
2006 7th International Symposium on Antennas, Propagation and EM Theory, ISAPE 2006, October 26, 2006 - October 29, 2006, Guilin, China
作者: He B.

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This paper proposes that the inter-layer separation distance (ISD) and the unit cell aligning error (UAE) are used as main variables to study the transmission performance attenuation of the double layer FSS configuration. The numerical analysis model for ISD and UAE was established and also was used to simulate the cross loop slot cell FSS transmission performance by the finite element and periodic moment method program. The double layer cross loop aperture FSS configuration designed was used as the numerical model. As a result of the numerical analysis it is shown that both ISD and UAE produce insertion transmission loss (ITL) and insertion phase distortion (IPD) directly. Furthermore ISD results in much loss of the amplitude of the transmitted signal for the FSS than UAE. It is significant for the designer for the multiplayer FSS to assign the fabricated error of the FSS dielectric layers. The UAE introduces the insertion phase variation badly.

Method for the fabrication of isometric mesh on the concave of a spherical substrate (EI CONFERENCE) 会议论文 OAI收割
2nd International Symposium on Advanced Optical Manufacturing and Testing Technologies - Advanced Optical Manufacturing and Testing Technologies, November 2, 2005 - November 5, 2005, Xian, China
作者: Feng X.-G.

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Metallic mesh has been widely used in electromagnetic interference windows. While the duty ratio of curved mesh equals to planar mesh' the theory of planar mesh may be applied to curved mesh according to equivalent-circuit model. So the idea that latitude lines intersect latitude lines to form isometric mesh on the concave of a sphere is put forward and the method of fabricating the mesh by concentric optical scan is introduced. The movement parts of equipment consist of an erection turning a horizontal dividing and a pitching dividing spindle. Firstly a spherical substrate is fixed on the horizontal dividing spindle that has been set horizontally on the erect turning spindle the substrate revolves around the axis of the erect spindle the tube of object lens that is fixed on the pitching dividing spindle steps at pitching direction and a revolving circuit of the substrate corresponds to a step of the tube. Gradually a set of latitude lines is attained. Afterward the substrate makes a quarter turn around the horizontal spindle another orientation latitude lines are also gained. Thus the isometric mesh on the concave of a spherical substrate is gained. The process comprises surface cleaning coating photoresist laser direct writing development evaporated film dissolving photoresist and plating. The fabricated spherical mesh has a line width of 7 m and a period of 600m. Experiment shows that infrared transmission and electromagnetism shield efficiency of the metallic mesh are relatively consistent with theoretical value.

Application of photoresist melting method to the fabrication of holographic grating (EI CONFERENCE) 会议论文 OAI收割
ICO20: Optical Devices and Instruments, August 21, 2005 - August 26, 2005, Changchun, China
作者: Li W.; Tang Y.; Yu H.; Gao J.; Li W.

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A new technique of reducing surface roughness of photoresist grating is presented. In this paper photoresist melting method which is low-cost short-period and easy realization is presented. In addition the influence of photoresist melting on the groove profile of the photoresist grating is investigated. Experimental results show that the surface roughness reduces due to surface tension when developed photoresist is heated to be melting state by this method. In experiment when the melted photoresist grating is etched by ion beam the surface relief grating possessing preferable groove profile is obtained on K9 glass substrate then the surface is evaporated by aluminum using vacuum evaporation holographic grating with preferable groove profile is successively fabricated.

Packaging technology of polymer/Si arrayed waveguide grating and their environmental stability (EI CONFERENCE) 会议论文 OAI收割
2005 6th International Conference on Electronics Packaging Technology, August 30, 2005 - September 2, 2005, Dameisha, Shenzhen, China
作者: Zhang Y.; Zhang X.; Zhang X.; Zhang X.; Wang F.

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Future optical communication systems will use more of the exceptional high bandwidth of optical fiber. Wavelength division multiplexing (WDM) systems are well suited to transport terabits of information via the fiber[1]. Multiplexers/ demultiplexers (MUX/DEMUX) are essential components for dense WDM systems. Several different kinds of multiplexer types have been developed in the past: (a) interference filters (b) fiber gratings and (c) planar lightwave circuit (PLC) MUX/DEMUXers[2 3]. The planar fabrication process of the last mentioned PLCs allows the realization of high performance filters with a large number of wavelength channels. Further an integration with other optical elements seems to be possible. Arrayed waveguide gratings (AWG) are a special kind of PLC-MUX/DEMUXers which are very attractive components for WDM systems because of their great flexibility in filter design[4 5]. Basically an AWG is an optical spectrograph built in planar waveguide technique. Typically AWGs works in a high grating order (50-250). For AWG multiplexer applications in communications systems a precise wavelength controllability and wavelength stability with long term is demanded. Recently a polymeric (especially fluorinated polymer with low optical absorption loss in the infrared region) AWG has attracted much attention because of its easy fabrication low cost possibility and a potential of integration with other polymer devices[6]. Standard AWGs however show a change of center wavelength with temperature. A method to prevent this temperature drift is to package the AWG together with a temperature controller in order to tune and fix the desired filter-wavelength. In this paper a 32-channel AWG was fabricated using a cross-linkable fluorinated poly (ether ether ketone) (FPEEK) its package technology and environmental stability were also discussed. 2005 IEEE.

A new method of image reconstruction with high resolution in X-ray coded aperture imaging (EI CONFERENCE) 会议论文 OAI收割
Laser-Generated, Synchrotron, and Other Laboratory X-Ray and EUV Sources, Optics, and Applications II, August 2, 2005 - August 4, 2005, San Diego, CA, United states
作者: Sun Y.; Sun Y.

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In the processing diagnosis of the inertia confinement fusion (ICF) the ring coded aperture imaging technique is applied in order to gain high space and time resolutions simultaneously. The key of acquiring high spatial resolution is how to obtain a point spread function of an imaging system. The common method is the firsthand projection method which is an approximate one. The x-ray diffraction effect is neglected in the method so the resolution of reconstructed image is decreased. We have derived the point spread function (PSF) of the ring coded aperture from scalar diffraction theory. And the Wiener filter is fabricated on the basis of the PSF. In National Key Laboratory of Laser Fusion at China Academy of Engineering Physics the imaging experiment on the diagnosis of ICF is completed using the ring coded aperture plate with inner diameter d1 = 250m and outer diameter d2 = 260m . The obtained coded image is processed by the Wiener filter which diffractive effect is considered. The processed results have shown that resolution and modulation contrast of acquired image are evidently better than the results obtained by the firsthand projection method.

Progress of si-based nanocrystalline luminescent materials 期刊论文 iSwitch采集
Chinese science bulletin, 2002, 卷号: 47, 期号: 15, 页码: 1233-1242
作者: Peng, YC; Zhao, XW; Fu, GS

收藏 | 浏览/下载：18/0 | 提交时间：2019/05/12

Si-based nanomaterials Fabricated method Structural characterization Light emitting mechanism Si-based photoelectronic devices