51 results on '"Shaojun Fu"'
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2. Mapping Lyman UV emission for diffuse sources
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Yuan Qian, Shijun Lei, Sebastian Buntrock, Thomas Kaufmann, Wei Zhang, Li Ji, Jianhua Guo, Zheng Lou, Shuping Yan, Zhanshan Wang, Ping Ruan, Qian Song, Daniel M. Schaadt, Beate Stelzer, Thomas Rauch, Shuangying Li, Xinfeng Li, Wen Chen, Jürgen Barnstedt, Taotao Fang, Jianfeng Yang, Jinlong Zhang, C. Kalkuhl, Klaus Werner, Mingsheng Cai, Kevin Meyer, Wei Liu, Lauro Conti, Thomas Schanz, Lei Deng, Shuinai Zhang, Sebastian Diebold, Sen Wang, Shaojun Fu, Lars Hanke, Wei Sun, Fu Li, Yilin Hong, Norbert Kappelmann, Keqiang Qiu, and Tinggui Wang more...
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Physics ,Lyman series ,Astronomy ,Primary science ,Radiation ,medicine.disease_cause ,Accretion (astrophysics) ,Galaxy ,Interstellar medium ,symbols.namesake ,Intergalactic medium ,medicine ,symbols ,Ultraviolet - Abstract
The CAFE (Census of warm-hot intergalactic medium, Accretion, and Feedback Explorer) and LyRIC (Lyman UV Radiation from Interstellar medium and Circum-galactic medium) have been proposed to the space agencies in China respectively. CAFE was first proposed as a joint scientific CAS-ESA small space mission in 2015. LyRIC was proposed as the independent external payload operating on the Chinese Space Station (CSS) in 2019. Both missions are dedicated to mapping the Lyman UV emissions ( ionized oxygen (OVI) resonance lines at 103.2 and 103.8 nm, and Lyman series) for the diffuse sources either in our Galaxy or the circum-galactic mediums of the nearby galaxies. We present the primary science objectives, mission concepts, the enabling technologies, as well as the current status. more...
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- 2020
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3. Design of soft x-ray varied-line-spacing grating based on electron beam lithography-near field lithography
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Dakui Lin, Stefanie Kroker, Zhengkun Liu, Keqiang Qiu, Ying Liu, Xiangdong Xu, Thomas Käsebier, Yilin Hong, Huoyao Chen, Shaojun Fu, and Ernst-Bernhard Kley
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Materials science ,business.industry ,Holography ,Near and far field ,Grating ,Laser ,law.invention ,Optics ,Resist ,law ,business ,Lithography ,Groove (music) ,Electron-beam lithography - Abstract
Soft x-ray varied line spacing grating (VLSG), which is a vital optical element for laser plasma diagnosis and spectrometry analysis, is conventionally fabricated by holographic lithography or mechanical ruling. In order to overcome the issues of the above fabrication methods, a method based on electron beam lithography-near field lithography (EBL-NFH) is proposed to make good use of the flexibility of EBL and the high throughput of NFH. In this paper, we showed a newly designed soft x-ray VLSG with a central groove density of 3600 lines/mm, which is to be realized based on EBL-NFH. First, the optimization of the spatial distribution of line density and groove profile of the VLSG was shown. As an important element in NFH, a fused silica mask plays a key role during NFH in order to obtain a required line density of VLSG. Therefore, second, the transfer relationship of spatial distribution of line densities between fused silica mask and resist grating was investigated in different exposure modes during NFH. We proposed a formulation about the transfer of line density to design of the groove density distribution of a fused silica grating mask. Finally, the spatial distribution of line densities between the fused silica mask, which is to be fabrication by using EBL, was demonstrated. more...
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- 2016
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4. Anti-reflective sub-wavelength structures at a wavelength of 441.6 nm for phase masks of near-field lithography
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Shaojun Fu, Yilin Hong, Ying Liu, Ernst-Bernhard Kley, Stefanie Kroker, Zhengkun Liu, Keqiang Qiu, Huoyao Chen, Thomas Käsebier, Xiangdong Xu, and Jinyu Li
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Materials science ,business.industry ,Phase (waves) ,Near and far field ,Polarization (waves) ,law.invention ,Wavelength ,Optics ,Nanolithography ,law ,Optoelectronics ,business ,Lithography ,Beam splitter ,Electron-beam lithography - Abstract
With the development of micro- & nanofabrication technology, micro- & nanostructures have been widely used in many fields, including spectroscopy, coding, sensor, subwavelength element, etc. With phase masks realized by a combination of electron beam lithography (EBL), near field lithography (NFH) has great potential to fabricate versatile nanostructures, because it combines the advantages of both lithographic methods. Currently, subwavelength structures attract much attention due to their various functions, such as antireflection, polarization beam splitter and filter. In this presentation, aiming at reducing the interface reflection of a fused silica mask of NFH at a wavelength of 441.6 nm and incidence angles of either 0° or 32°. First, we will compare the difference of antireflection property of one-dimensional (1D) and two-dimensional (2D) subwavelength structures with line density of 3600 lines/mm by simulation. Then, the optimized 1D and 2D subwavelength structures with 3600 lines/mm will be fabricated by using EBL-NFH method. Finally, the antireflection property of these 1D and 2D subwavelength structures will be characterized at the wavelength of 441.6 nm. more...
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- 2016
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5. Method for ion beam etching in angles with multi-layers model
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Zhengkun Liu, Zeng Siwei, Lixiang Wu, Shaojun Fu, Yilin Hong, and Keqiang Qiu
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Optics ,Materials science ,Ion beam ,Sputtering ,business.industry ,Etching (microfabrication) ,Dry etching ,Grating ,Reactive-ion etching ,business ,Isotropic etching ,Groove (music) - Abstract
A new method for controlling the groove profiles of diffraction gratings which changes the etching angle and etching time, meanwhile divides the etching area in the substrate into multi-layers to have a good approximation for the theory is introduced. We put forward a multi-layers etching model on the base of the ion bean sputtering (IBS) which can calculate the etching time and etching angle. We test the curved grooves profiles and get the optimizations for the number of the multi-layers, etching time and etching time in this model. Also a photoresist grating is applied for the etching experiment. The results indicate that the optimized parameters such as the number of the multi-layers result in a smaller root mean square deviation (RMSD) between the theory and the real etching result which show good agreement with the theoretical groove within the variation of ±6% of the etching rate. The simulation predictions and experimental results show that the multi-layers etching model to control the groove profiles of diffraction gratings is available. more...
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- 2016
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6. Fabrication of large-aperture, high efficiency, Fresnel diffractive membrane optic for space telescope
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Ganghua Yin, Xiangdong Xu, Zhengkun Liu, Shaojun Fu, Jianchao Jiao, Mengjuan Li, and Jian Zhang
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Wavefront ,Physics ,Diffraction ,Fabrication ,business.industry ,Aperture ,Astrophysics::Instrumentation and Methods for Astrophysics ,Physics::Optics ,Large aperture ,Diffraction efficiency ,01 natural sciences ,010309 optics ,Optics ,Membrane ,Spitzer Space Telescope ,0103 physical sciences ,Optoelectronics ,business - Abstract
Diffractive optical system can be a favorable choice for large-aperture space telescope to reduce the mass and size of image system. To meet the demand of large-aperture, high efficiency, lightweight diffractive optic for high resolution remote sensing, a 200 mm diameter, 20 μmthick, 4-level diffractive membrane fabricated is shown to have over 62% diffraction efficiency into the +1 order, with 0.051 efficiency RMS. Over 66% diffraction efficiency is achieved for a 100 mm aperture membrane, with 0.023 efficiency RMS. The membrane thickness uniformity control is discussed and 8 nm wave front error RMS is achieved in 100 mm diameter. more...
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- 2016
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7. Improving the spectral resolution of soft x-ray flat-field spectrometer with multi-area gratings
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Qingbo Wang, Shaojun Fu, Zhengkun Liu, and Huoyao Chen
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Diffraction ,Physics ,Spectrometer ,Field (physics) ,business.industry ,Astrophysics::Instrumentation and Methods for Astrophysics ,Physics::Optics ,Grating ,Ray tracing (physics) ,Wavelength ,Optics ,Perpendicular ,Spectral resolution ,business - Abstract
The ideal focal curve for the soft x-ray flat-field spectrometer is a straight line, but the real one is not, thus the inconformity of aberrations between different wavelengths in the working waveband is inevitable. In order to further reduce aberrations and improve spectral resolutions, multi-area gratings (divided perpendicular the direction of grating grooves) are devised. Firstly, the grating is divided into three areas, and the spectral aberrations for these areas are analyzed by means of ray tracing. Then, diffraction efficiencies for the areas with worse aberrations should be reduced to lower the proportion regional aberrations contributing to the overall aberration, therefore better spectral image could be obtained and the spectral resolution would be improved. Theoretical analysis demonstrates that: using multi-area grating, the spectral resolutions at wavelength of 0.8 and 1.1nm are increased from 123 and 333 to 401 and 671, respectively. At the same time, the spectral resolutions at other wavelengths are not reduced. more...
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- 2013
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8. Improve the laser damage resistance of fused silica by wet surface cleaning and optimized HF etch process
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Xiaolong Jiang, Huanle Rao, Shaojun Fu, and Ying Liu
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Materials science ,Metal impurities ,technology, industry, and agriculture ,Laser ,Surface cleaning ,law.invention ,Metal ,Chemical engineering ,Laser damage ,law ,visual_art ,visual_art.visual_art_medium ,Ultrasonic sensor ,Leaching (metallurgy) - Abstract
Fabrication-induced metal contaminations and subsurface damage are generally identified as the laser damage initiators that are responsible for the laser induced damage in fused silica. In this paper, the removal of those two initiators are realized by two methods: wet chemical surface cleaning and optimized HF-based etch process. Two kinds of chemical leaching are used to removing the Ce and other metal impurities respectively. In order prevent the redeposition of the reactive byproducts during HF etch process, we optimized the traditional HF etch process in two ways: absence of NH 4 F in etch solution and presence of megasonic and ultrasonic agitation during and after etch respectively. And laser damage tests show that these two treatments greatly improve the laser damage resistance of fused silica. more...
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- 2013
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9. Study on the precision measurement of high-flux large aperture sampling grating
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Jianhong Wu, Yong-quan Chen, Ya-xuan Duan, Haoyu Yuan, Shaojun Fu, and Zhi-tao Peng
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Diffraction ,Physics ,business.industry ,Aperture ,Physics::Optics ,Sampling (statistics) ,Grating ,Optics ,Data acquisition ,Calibration ,Focal length ,business ,Diffraction grating ,Computer Science::Databases - Abstract
This paper describes an effective method for the measurements of large aperture sampling grating , the sampling efficiency the sampling focal length and the sampling angle. By using a 351nm collimation laser source to scan the full aperture of the sampling grating in every subregion, the diffraction power of q0q order and q+1q order can be obtained synchronously by two standard integrating balls, And then by calculating the sampling efficiency of this subregion and splicing the acquisition data, we can get the averaged grating sampling efficiency in the full aperture .Based on this method, we can effectively eliminate the effect of the output instability of laser source, decrease the uncertainty of test results. According to the fabrication principle of the sampling grating , measurements for the sampling focal length and the sampling angle can be performed. Test rersults indicate that this method can be used to measure large aperture sampling gratings . more...
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- 2012
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10. Fabrication of a new type of transmission grating with holography interferometry and wet anisotropic etching
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Xiangdong Xu, Shaojun Fu, Ying Liu, Yong Chen, Yilin Hong, Keqiang Qiu, and Zhenkun Liu
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Diffraction ,Materials science ,Holographic grating ,business.industry ,Holography ,Grating ,Diffraction efficiency ,law.invention ,Ultrasonic grating ,Optics ,law ,Blazed grating ,Optoelectronics ,business ,Diffraction grating - Abstract
As a new type of grating, the freestanding blazed transmission grating combines the advantages of traditional transmission gratings (low mass, relaxed alignment and flatness figure insensitivity) with those of reflection gratings (high broadband diffraction efficiency, high spectral resolution). A freestanding blazed transmission grating with period of 1μm was successfully fabricated by holographic lithography and anisotropic wet etching of silicon. The duty cycle is about 0.13. The aspect ratio of a single grating bar is about 77. The thickness is 10μm and the open area fraction is about 58.8%. The size of a single die is 15mm×15mm divided into four 5mm ×5mm windows. The diffraction efficiency of the grating was measured at the National Synchrotron Radiation Laboratory in the wavelength region of 5-50nm. The results show a strong blazing effect in the direction of specular reflection from mirror-like grating sidewalls, as expected. more...
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- 2012
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11. Mechanical polishing to improve uniformity of beam sampling grating and its effects on laser-induced damage
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Ying Liu, Shaojun Fu, Zhengkun Liu, and Huanle Rao
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Diffraction ,Materials science ,Ion beam ,business.industry ,Polishing ,Grating ,Laser ,Diffraction efficiency ,law.invention ,Optics ,law ,business ,Inertial confinement fusion ,Beam (structure) - Abstract
As an important optical element, beam sampling grating (BSG) is used in the terminal of inertial confinement fusion (ICF) drivers. It can provide a very slight sampling beam for the precision diagnosing of laser energy and wavefront distortion. However, in practice, its non-uniform diffraction efficiency seriously influences the accurate signal of sampling beam, and finally affects diagnostic ability. BSG is usually fabricated by holographic ion beam etched (HIBE) process. In this paper, a mechanical polishing processing technology was used to improve uniformity of the diffraction efficiency of BSG after HIBE. In the processing, cerium oxide (CeO 2 ) was used to polish the local areas of grating where exhibit higher diffraction efficiency with the purpose of changing the depth of grating profile, and then they have similar efficiency with the surrounding areas. By iteration of the above process, BSG finally achieve the improved uniformity of diffraction efficiency over the area of a 430 x 430 mm 2 . The RMS of diffraction efficiency of BSG after mechanical polishing shows great reduction down to 4.8% as compared with that of the as-polished RMS of 21%. The effects of this processing on laser damage was characterized by the measuring the LIDT for the laser radiations of 355nm. more...
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- 2011
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12. Polymeric nanostructures fabricated by dynamic nanoinscribing technique and its applications
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Shaojun Fu, Qisheng Tang, Liangjin Ge, Jian Jin, Li Xin, and Xudi Wang
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chemistry.chemical_classification ,Nanostructure ,Materials science ,Silicon ,chemistry ,Nanophotonics ,chemistry.chemical_element ,Nanotechnology ,Nanofluidics ,Polymer ,Grating ,Biosensor ,Nanoscopic scale - Abstract
Nanoscale grating structure can be utilized in many practical applications in optics, flat-panel displays, and biosensors. Dynamic nanoinscribing (DNI) technique was newly developed to create large-area and truly continuous nanograting patterns in a variety of metal or polymer materials with feature size down to sub-50 nm and at very high speed. In this paper we investigate the nanopatterning of PC and SU-8 by DNI process and then take advantage of its superior optical and thermal properties to explore its applications in nanooptics and nanofluidics. To carry out nanoinscribing, silicon grating templates with different periods were first fabricated. The inscribing property of PC and SU-8 under various pressures and temperatures was systematically studied, in which the experimental results were compared with the simulation results described by a modified equation of Squeezed flow. Inscribed polymeric gratings with period of 700nm were achieved and excellent uniformity can now be routinely replicated using this optimized process. Using this technique, free-standing subwavelenth gratings based on SU-8 are successfully fabricated and their performance are characterized. The inscribed polymeric gratings could also be sealed with another bare layer thermally to serve as enclosed channels after oxygen plasma treatment. The fabricated nanofluidic channels were characterized using spontaneous capillary filling with dyed water, demonstrating good quality of sealing. more...
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- 2011
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13. Poly (ethylene terephthalate) (PET) micro/nanostructures fabricated by nanoimprint and its applications
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Qisheng Tang, Xiaojun Li, Wenrui Tian, Jian Jin, Shaojun Fu, Xudi Wang, and Yanlin Liao
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Diffraction ,Materials science ,Nanostructure ,Fabrication ,law ,Phase (matter) ,Resolution (electron density) ,Nanophotonics ,Nanotechnology ,Grating ,Nanoimprint lithography ,law.invention - Abstract
In this paper, we present a novel method for the fabrication of high density pattern in PET foils employing nanoimprint lithorgraphy. The temperature and pressure dependence on the imprinted pattern were investigated. Well resolved PET nanopatterns (sub-100nm resolution) were transferred successfully. It is observed that the grating with different trench depths will demonstrates corresponding changes of diffraction intensity distribution. The grating imprinted in PET foils could broader applications in the manufacture of nanophotonic structures owing to its excellent flexibility and transparency. Based on the optimized imprint process, a novel method for the fabrication of phase gratings and nanochannels is presented. This developed process can find broader applications in the manufacture of nanofluidic channels and other nanophotonic structures. more...
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- 2010
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14. Wet-cleaning of contaminants on the surface of multilayer dielectric pulse compressor gratings by the Piranha solution
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Shangbi Chen, Xiangdong Xu, Shaojun Fu, and Bin Sheng
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genetic structures ,Photoemission spectroscopy ,Scanning electron microscope ,Analytical chemistry ,Wet cleaning ,Dielectric ,Laser ,law.invention ,chemistry.chemical_compound ,chemistry ,X-ray photoelectron spectroscopy ,law ,Radiation damage ,Composite material ,Piranha solution - Abstract
Contaminants are deemed to be the initial source of optical-damage mechanisms as well as the main reason to decrease the Laser Induced Damage Threshold (LIDT) of multilayer dielectric pulse compressor gratings (PCG). In this paper, the Piranha solution was used effectively and nondestructively to remove the residual contaminants on the surface of PCG. The surface cleanliness was evaluated by Scanning Electron Microscopy (SEM) and X-ray Photoelectron Spectroscopy (XPS). The higher removal efficiency was achieved with more times of multiple-cleaning by fresh Piranha solution which has an effectiveness for a given period of time. more...
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- 2010
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15. A new system for measuring the diffraction efficiency of large aperture gratings
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Zhengkun Liu, Xiangdong Xu, Xiaowei Zhou, Xiao Wang, and Shaojun Fu
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Diffraction ,Materials science ,business.industry ,Stray light ,Physics::Optics ,Acousto-optics ,Grating ,Diffraction efficiency ,Ray ,law.invention ,Optics ,law ,Shutter ,Blazed grating ,Optoelectronics ,Physics::Atomic Physics ,business - Abstract
A simple and new system for measuring the diffraction efficiency of large aperture gratings at littrow angle is established in this paper. The reference grating Po, double beams and timer with shutter have been draw into the system for eliminating the impact of polarization and stray light, fluctuation of incident light, and the fatigue of photodetector. A program is designed to scan, measure and calculate the diffraction efficiency of the gratings automatically. The diffraction efficiency accuracy measured for the gratings is increased by ~1% with this system. To achieve more measured accuracy, additional beam of reflection light should be imported. more...
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- 2010
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16. Soft substrate as a sacrificial layer for fabrication free-standing SU-8-based nanofluidic system
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Shaojun Fu, Xin Li, Jian Jin, Xudi Wang, Yangchao Tian, and Xiaojun Li
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Fabrication ,Materials science ,Nanotechnology ,Substrate (printing) ,medicine.disease_cause ,Nanoimprint lithography ,law.invention ,Polyester ,law ,Mold ,medicine ,Nanometre ,Wafer ,Layer (electronics) - Abstract
In this paper, we describe a new fabrication process utilizing polydimethylesiloxane (PDMS) and polyester (PET) as a sacrificial substrate for fabricating free-standing SU-8-based nanofluidic system. The soft substrate permits SU-8 UV cured patterning and layer-to-layer bonding, and allows the SU-8 structures to be easily peeled off from the substrate after complete fabrication. In the process, PDMS-on glass is used as a handling wafer, on which SU-8 based trenches is imprinted by a flexible film mold using low-pressure nanoimprint lithography. The reservoir pattern of SU-8 is fabricated on the bonding layer, in which PET serves as substrate. The nanochannel is sealed by optimized bonding process, which is flexible and easily controllable with the use of soft substrate as a sacrificial layer. After bonding process, PDMS and PET could be easily peeled off from nanaofluidic system. The SEM results shows that the height of the fully enclosed nanochannels will be about hundreds nanometer. Large area of free standing SU-8 structure layers are successfully fabricated and peeled off from the soft substrate layer as single continuous sheets. more...
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- 2010
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17. Design of multilayer grating in VUV spectrum by rigorous coupled-wave method
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Huoyao Chen, Shaojun Fu, Shengnan He, Ying Liu, and Keqiang Qiu
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Diffraction ,Materials science ,Holographic grating ,business.industry ,Physics::Optics ,Grating ,Diffraction efficiency ,law.invention ,Ultrasonic grating ,Optics ,law ,Blazed grating ,Transmittance ,business ,Monochromator - Abstract
The rigorous coupled-wave method (RCWM) is extended to calculate the diffraction efficiency of multilayer grating in spectrum with strong absorption. This paper gives a detailed algorithm analysis of the RCWM, an enhanced, numerically stable transmittance matrix approach applied to homogenous layered media is generalized for multilayer grating structure. In order to calculate in the lossy medium, the wave vector of electric field is redefined. This method is programmed to design multilayer grating which is expected to use on Seya-Namioka synchrotron monochromator in vacuum ultraviolet (VUV) spectrum. The influence on diffraction efficiency caused by grating profile and multilayer stack is analyzed theoretically. The diffraction efficiencies of well-designed multilayer gratings are all greater than 10% in 50-110nm region, and they are about two to three times higher than that of the single metallic layer grating which is being used on Seya-Namioka monochromator now. more...
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- 2010
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18. Applications of INNOSLAB lasers with tailored beam profiles
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Shaojun Fu, Alexander Schell, Keming Du, Claus-Rüdiger Haas, Daijun Li, and Peng Shi
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Dye laser ,Materials science ,business.industry ,Physics::Optics ,Pulse duration ,Velocimetry ,Laser ,Pulse (physics) ,Power (physics) ,law.invention ,Optics ,law ,Laser beam quality ,business ,Beam (structure) - Abstract
INNOSLAB lasers are characterized by: short pulse length and high peak power, high pulse repetition rate, high beam quality and flexibility in beam profile, from circular beam profile, through line shaped one dimensional Top-hat, to two dimensional top-hat with rectangular or square cross section. Their tailor able beam profiles open for INNOSLAB laser a variety of applications with high energy efficiency, such as glass milling, parallel scribing, high throughput ablation, particle imaging velocimetry and pumping of dye lasers. more...
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- 2010
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19. Recent progresses in INNOSLAB lasers and their harmonic generation
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Daijun Li, Xiaomeng Liu, Jun Chen, Jingxiong Wang, Shaojun Fu, Alexander Shell, Claus-Rüdiger Haas, Bingsong Qi, Keming Du, and Peng Shi
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Materials science ,business.industry ,Physics::Optics ,Pulse duration ,Laser ,Q-switching ,law.invention ,Pulse (physics) ,chemistry.chemical_compound ,Optics ,chemistry ,law ,Harmonic ,Lithium triborate ,High harmonic generation ,Laser beam quality ,business - Abstract
Through an optimal combination of crystal shape, cooling and resonator design, InnoSlab lasers possess unified advantageous features of short pulse duration and high peak output power, high pulse repetition rate, high beam quality and high flexibility in beam profile, from circular beam profile, through line shaped one dimensional Top-hat, to two dimensional Top-hat with rectangular cross section. We report diode end pumped, electrooptically q-switched Nd:YLF, Nd:YAG and Nd:YVO4 slab laser and their efficient harmonic generation in near field. Using oscillator/amplifier with Nd:YAG slabs over 50mJ pulse energy at 6kHz was obtained. The pulse length is 7ns and the peak power is as high as 7MW. With Nd:YVO4 slabs 400W average power at 50kHz was obtained. The pulse length is as short as 8ns. Because of the high peak power over 300W second harmonic is achieved by two LBO crystals. more...
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- 2010
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20. Experimental study of roof filling rate during thermal bonding of polymer microchannel sealing
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Shaojun Fu, Yun Jiang, Liangjin Ge, Jingjing Lu, and Xudi Wang
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chemistry.chemical_classification ,Filling rate ,Microchannel ,Materials science ,chemistry ,Capillary action ,Flow (psychology) ,Meniscus ,Nanotechnology ,Polymer ,Composite material ,Thermal bonding ,Roof - Abstract
Direct thermal bonding approaches are especially desirable as they allow formation of enclosed microchannels with uniform surfaces composed entirely of the same polymeric material. It is often believed that the main phenomenon involved during thermal bonding is a chain entanglement of the polymers over the boundary. If the temperature is too high and/or the application of the force is too long then the polymer will flow and refill the channels caused by capillary forces, called as roof filling phenomenon. In order to understand this process more fully, we describe an experimental method for characterizing the roof filling rate inside a microchannel by measuring the polymer marching velocity or position of a capillary meniscus during thermal bonding. 1D nanochannels was fabricated succesfully and the vertical dimension was well controlled according to the top filling mechnism. more...
- Published
- 2008
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21. High aspect ratio grating fabrication in SU-8 resist by UV-Curing nanoimprint
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Liangjin Ge, Xudi Wang, Shaojun Fu, and Jingjing Lu
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Fabrication ,Materials science ,business.industry ,Nanophotonics ,Grating ,Nanoimprint lithography ,law.invention ,Nanolithography ,Resist ,law ,UV curing ,Deep reactive-ion etching ,Optoelectronics ,business - Abstract
UV curing nanoimprint is demonstrated for high aspect ratio gratings fabrication based on SU-8 for nanophotonics and biochemical applications. The defects, which are caused by stress and friction between mold and resist and air bubbles are key issues. To eliminate the defects, the process parameters, such as imprinting pressure, baking time and demolding temperature, are optimized. SU-8 grating with 150nm in width and 1.5µm is presented with good uniformity in large area using Si template fabricated by non-switching DRIE process. The process could find broader applications in the manufacture of biochemical devices and nanophotonic structures. more...
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- 2008
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22. Comparative study of surface roughness with power spectral density and multifractal spectrum
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Shaojun Fu, Hongjun Zhou, Xiangdong Xu, Shuyi Gan, Ying Liu, Tonglin Huo, Yilin Hong, and Qing Zhou
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business.industry ,Spectral density ,Sampling (statistics) ,Multifractal system ,Surface finish ,Fractal analysis ,Fractal ,Optics ,Position (vector) ,mental disorders ,Surface roughness ,skin and connective tissue diseases ,business ,psychological phenomena and processes ,Astrophysics::Galaxy Astrophysics ,Mathematics - Abstract
This paper presents a comparative studied of surface roughness. Samples were first measured by atomic force microscope (AFM). The acquired height data was then processed to calculate their power spectral density (PSD) and multi-fractal spectrum (MFS). The calculation results indicate that MFS of different samples with same sampling length differs significantly from each other, while the MFS of the same sample with different sampling length or different sampling position is quite similar. The calculation also shows that MFS is very sensitive to particles or scratches appeared on the surface. The PSD of the same data acquired from these samples are also presented for comparison. It is clear from the calculation results that the PSD curves vary with the sampling position and sampling length, thus makes the evaluation uncertain. No quantitative index available from PSD, only qualitative information obtained. Comparatively, MFS is better in description of a surface roughness. more...
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- 2007
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23. Measuring the parallelism of the splitter grating used in a soft X-ray laser interferometer
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Zhengkun Liu, Ying Liu, Xin Tan, and Shaojun Fu
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Diffraction ,Physics ,Distributed feedback laser ,Holographic grating ,business.industry ,Physics::Optics ,Grating ,law.invention ,Interferometry ,Optics ,law ,Blazed grating ,Astronomical interferometer ,Physics::Atomic Physics ,business ,Diffraction grating - Abstract
We present new progress of the diffraction grating interferometer being pre-aligned used a double frequency grating. To measure the parallelism of the double frequency grating to a nicety before being built in the interferometer, a device based on Diffraction Technique for measuring the parallelism of the double frequency grating is designed. It is built of a semiconductor laser, a collimator, gratings, a precision turnplate, a beeline workbench, a redressal shelves, a ccd detector. The system error of the device is analyzed in this paper, and the parallelism of the double frequency grating is measured by this device. The results demonstrate that the diffraction measuring device suits the parallelism measured the diffracting grating interferometer based on the double frequency grating of that parallelism can attain a high pre-aligning precision. more...
- Published
- 2007
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24. Study of magnetic nanostructures fabricated using laser interference lithography
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Xiangdong Xu, Shaojun Fu, Yin Liu, Pengshou Xu, Zijun Zhang, Yuxian Guo, Jie Wang, and Youmei Chen
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Materials science ,Kerr effect ,business.industry ,Magnetism ,Physics::Optics ,Laser ,Computer Science::Other ,law.invention ,Standing wave ,Condensed Matter::Materials Science ,Hysteresis ,Optics ,Etching (microfabrication) ,law ,Patterned media ,business ,Lithography - Abstract
Magnetic submicron meter structures were fabricated on Co 0.9 Fe 0.1 films by laser interference lithography combined with ion beam etching. The vertical standing wave was restrained by using proper exposure dose and appropriate development time. Hysteresis loops of the magnetic film and magnetic patterns were presented by surface magneto-optical Kerr effect. The difference magnetism between magnetic patterns with different critical sizes and the film was discussed. more...
- Published
- 2007
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25. Design and fabrication of soft x-ray transmission phase gratings
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Yilin Hong, Xiangdong Xu, Shaojun Fu, Keqiang Qiu, and Ying Liu
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Diffraction ,Materials science ,Holographic grating ,business.industry ,Holography ,Physics::Optics ,Grating ,Diffraction efficiency ,law.invention ,Ultrasonic grating ,Optics ,law ,Blazed grating ,business ,Diffraction grating - Abstract
A binary transmission phase grating is designed to operate as a dispersive element used in soft x-ray plasma diagnostic in ICF (inertial confinement fusion). The first and zero orders diffraction efficiency is simulated as a function of wave length and grating thickness. It is shown that the first order diffraction efficiency of a transmission phase grating can be up to 23.3% of the incident light, whereas that is not more than 10% for a conventional amplitude transmission grating. The transmission phase grating is fabricated in gold film supported by polyimide membranes using holography and ion beam etching method. The primary experimental results are presented. more...
- Published
- 2007
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26. Optimizing the varied line-space grating with the curvature of grating substrate
- Author
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Zhengkun Liu, Shaojun Fu, Ying Liu, Xiangdong Xu, Bin Liu, and Yilin Hong
- Subjects
Materials science ,Holographic grating ,business.industry ,Plane (geometry) ,Physics::Optics ,Grating ,Curvature ,law.invention ,Ultrasonic grating ,Optics ,law ,Blazed grating ,business ,Diffraction grating ,Groove (music) - Abstract
Parameters of two spherical waves are firstly optimized to get the exact groove densities of diffractive gratings. Consequently, the groove density differences between on the plane and on the curved substrates are derived. Therefore, some experimental results are provided to demonstrate the validity of this method above. Meanwhile, the curvatures of the substrates are measured three times by using long trace profiler (LTP), which assures the repeatability of the bending technique for grating substrates. At last, the advantage of this method is exhibited through comparing the errors of grating groove density fabricated by this technique with only two spherical waves. more...
- Published
- 2007
- Full Text
- View/download PDF
27. Rapid nanofabrication with high density pattern with UVN30 chemically amplified resist
- Author
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Shaojun Fu, Yifang Chen, Zheng Cui, and Xudi Wang
- Subjects
Materials science ,Nanolithography ,Fabrication ,Resist ,law ,Proximity effect (electron beam lithography) ,Nanophotonics ,Deep reactive-ion etching ,Nanotechnology ,Electron-beam lithography ,Nanoimprint lithography ,law.invention - Abstract
As a chemically amplified resist, UVN30 has been evaluated for mask use in high density pattern rapid fabrication by electron beam lithography. This resist displays excellent sensitivity and reasonable resolution for dense features. At optimum conditions proximity effect is eliminated and 75 nm and 150 nm dense lines resolved in a 300 nm thick film with writing field of 1mm 2 . With UVN30 mask, Si nanostructures are etched by non-switch DRIE etch chemistry developed in this work, which achieves high etch rate and smooth sidewall. This method is a promising technique for fast speed fabrication of nanophotonics, nanochannels and Si master stamps for nanoimprint. more...
- Published
- 2007
- Full Text
- View/download PDF
28. Reactive ion beam etching of large-aperture multilayer diffraction gratings by radio frequency ion beam source
- Author
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Shaojun Fu, Xiangdong Xu, Dequan Xu, Ying Liu, and Yilin Hong
- Subjects
Diffraction ,Ion beam ,Chemistry ,business.industry ,Physics::Optics ,Grating ,Diffraction efficiency ,Laser ,Transverse mode ,law.invention ,Length measurement ,Optics ,law ,business ,Diffraction grating - Abstract
The major etching processes of a large-aperture multilayer diffraction grating, including the uniformity of the ion beam current along the major axis and the on-line measurement of the diffraction intensity distribution are described. A large-aperture ion beam etcher with radio frequency linear source has been developed to fabricate large-aperture diffractive optical elements. The length with ±5.1% uniformity of the ion beam current distribution along the major axis is 30 cm. A series of multilayer diffraction gratings were etched successfully by using this etcher with CHF 3 chemistry. Multilayer diffraction gratings on a 80 mm×150 mm BK7 substrate etched for laser systems are shown. The grating exhibits an averaged diffraction efficiency about 96% at TE polarization of 1 064 nm light viewed at Littrow angle. more...
- Published
- 2007
- Full Text
- View/download PDF
29. Study on fiber position sensor based on wavelength encoding plane variable-line-space gratings
- Author
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Zhijun Meng, Weiping Yao, Weijian Tian, Jun Lou, and Shaojun Fu
- Subjects
Diffraction ,Materials science ,business.industry ,Holography ,Physics::Optics ,Grating ,Ray ,law.invention ,Wavelength ,Optics ,law ,Fiber optic sensor ,Position (vector) ,business ,Position sensor - Abstract
In recent years, a new fiber position sensor based on wavelength encoding plane variable-line-space gratings is developed and has attracted more and more interest. In this paper the theoretical background to the fiber position sensor concept is briefly described. The large slope groove density distribution variable-line-space grating with holographic recording is used in fiber position sensor. The preliminary results obtained were quite noteworthy. Due to the unevenness of the incident light intensity in different wavelength, the diffractive intensity of different position change quickly. The diffraction wavelength curve of the system is given. The resolution of the position sensor is also discussed in this paper. more...
- Published
- 2007
- Full Text
- View/download PDF
30. Amending the uniformity of ion beam current density profile
- Author
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Xiaowei Zhou, Dequan Xu, Xiangdong Xu, Ying Liu, and Shaojun Fu
- Subjects
Beam diameter ,Ion beam ,business.industry ,Chemistry ,Faraday cup ,Ion source ,symbols.namesake ,Optics ,symbols ,Physics::Accelerator Physics ,M squared ,Laser beam quality ,business ,Current density ,Beam (structure) - Abstract
The uniformity of ion beam current density profile has been amended by changing the flow of the gas and making a new beam channel. The platform scanned in the horizontal orientation in this experiment, so the horizontal ion beam current distribution had hardly any effect on the etching uniformity and amending the ion beam current density profile in the vertical orientation was sufficient for the purpose of plat etching profile. The ratio of the ion source’s working gas inputs has some effect for the uniformity and a ratio of 6.50sccm: 8.00sccm: 9.60sccm of the three gas inputs flow1: flow2: flow3 will lead to a more uniform profile. According to the horizontal distribution and the original vertical ion beam current density distribution measured by Faraday Cup, a new beam channel was made. The uniformity of ion beam current density profile is enhanced from ±4.31﹪to ±1.96﹪ in this experiment. more...
- Published
- 2007
- Full Text
- View/download PDF
31. Simulation of optical surfaces and their PSD study
- Author
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Yilin Hong, Yinhe Bao, Ying Liu, Shaojun Fu, Shuyi Gan, and Xiangdong Xu
- Subjects
Surface (mathematics) ,Range (mathematics) ,Engineering ,Optics ,business.industry ,Component (UML) ,Acoustics ,Surface roughness ,Process (computing) ,Function (mathematics) ,Surface finish ,business ,Measure (mathematics) - Abstract
The performance of a optical component is greatly dependent on its surfaces. There are many ways to measure and evaluate a surface so far, but actually no one knows exactly what a "real" surface likes, and thus makes some measurement unexplainable. This paper develops a way to construct various synthetic surfaces. Referred to actual AFM measurement, regular or irregular surfaces can be created and studied. Bumps, scratches, granules, profile errors and other construction elements can be added to form a very complicated virtual surface. The number, size and distribution of these elements can be changed, and if necessary, the surface roughness can be controlled in a specialized range. As these surfaces are created synthetically, we know exactly what construction these surface contain. The height data of created virtual surfaces can be transferred into the file that AFM instrument can read and handle. As a typical example, a very complicated surface is created step by step in this paper, and its PSD for each step are calculated. This process mikes it very clear how the surface component element affect its PSD function, and is benefit to our better understanding of real surface construction. more...
- Published
- 2007
- Full Text
- View/download PDF
32. The splitter grating used in the soft x-ray laser interferometer for plasma diagnosis
- Author
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Ying Liu, Xin Tan, and Shaojun Fu
- Subjects
Diffraction ,Physics ,Holographic grating ,business.industry ,Physics::Optics ,Grating ,Mach–Zehnder interferometer ,law.invention ,Interferometry ,Ultrasonic grating ,Optics ,law ,Blazed grating ,business ,Diffraction grating - Abstract
The short wavelength, high brightness and good spatial coherence of soft x-ray lasers make them ideal sources for the diagnostics of dense plasmas. As a widely used diagnosing tool in the research of laser-produced plasma, interferometry has many advantages in the accurate measurement of the plasma electron density because it directly gives refraction index mapping from the interference pattern processing. The electron density gradient and electron density of larger variety plasma will be probed by the soft X-ray diffraction grating Mach-Zehnder interferometer (DGI). At the wavelength 13.9nm which our DGI uses, we fabricate a laminar grating used as the splitter grating. Its groove density is 1000g/mm, groove depth is 13nm, duty cycle is 0.4±10%. The zero and first diffracted order beams have an equal metrical diffraction efficiency about 25 percent at 81.3 degrees, and the maximum of the product is 7.6 percent at 81.2 degrees. The results illustrate the laminar grating is suitable for being used as a new pattern splitter grating at the wavelength 13.9nm. more...
- Published
- 2007
- Full Text
- View/download PDF
33. Methods of controlling grooves profile and the duty cycle of gold transmission phase gratings
- Author
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Yilin Hong, Keqiang Qiu, Xiangdong Xu, Ying Liu, and Shaojun Fu
- Subjects
Materials science ,Ion beam ,business.industry ,Holography ,Phase (waves) ,law.invention ,Standing wave ,Optics ,law ,Duty cycle ,Etching (microfabrication) ,business ,Diffraction grating ,Groove (music) - Abstract
It is known that rectangular grooves profile and various duty cycles (line to pitch) are required to attain maximum efficiency. The gold transmission phase gratings have been fabricated using holography and ion-beam etching techniques. The latent image monitoring technique and real time end-point detection technique were utilized to improve control of the shape of grooves and duty cycle during exposure and development, respectively. It is difficult to produce gratings with larger duty cycle in photoresist on gold for standing wave, nevertheless it is revealed in our work that the duty cycle can be more than 0.4 for the case for photoresist on gold substrates if development is stopped where the slope of the monitoring curve begins to drop off, not at the peak of the diffracted signal. In ion-beam milling, the influence of redeposition on the shape of grooves and duty cycle has been overcome by using a thin mask of Chromium with a comparatively low ion-etch rate and tilting and rotating substrates beneath the ion beam. Finally, some gold phase gratings with the duty cycles in the range of 0.25-0.45 have been obtained, whose duty cycle value is about 0.45, and their grooves profile is trapezoidal profile whose left and right facets are both more than 83 degrees approximately. more...
- Published
- 2007
- Full Text
- View/download PDF
34. Fabrication of CoFe nanostructures by holographic lithography
- Author
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Shaojun Fu, Zijun Zhang, Xiangdong Xu, Jianwang Cai, Pengshou Xu, Ying Liu, Yuxian Guo, Yilin Hong, Xudi Wang, and Jie Wang
- Subjects
Materials science ,Fabrication ,Magnetism ,business.industry ,Physics::Optics ,law.invention ,Interference lithography ,SQUID ,Condensed Matter::Materials Science ,Optics ,law ,Etching (microfabrication) ,Patterned media ,Optoelectronics ,Thin film ,business ,Lithography - Abstract
A novel process that combines interference lithography and ion beam etching is presented for fabrication of magnetic submicron structures and nanostructures in this paper. Instead of an antireflective coating, vertical standing wave patterns were removed using oxygen descumming process. A series of magnetic submicronmeter structures were fabricated on Co 0.9 Fe 0.1 films by this technique. Fabrication of magnetic nanostructures was performed by using a high exposure dose and modifications in optimized development c onditions. A thin Au film was deposited on the sidewall of the magnetic nanostructures to avoid the oxidation of Co and Fe. The effect of this method was confirmed by X-ray photoelectron spectroscopy (XPS). Hysteresis loops measured by a highly sensitive superconducting quantum interference device (SQUID) technique show the different magnetic properties of the magnetic patterns with different critical dimensions. Keywords: holographic lithography, patterned media, oxygen descumming, hysteresis loops more...
- Published
- 2007
- Full Text
- View/download PDF
35. Free-standing SU-8 gratings fabricated by sacrificial layer-assisted UV curing imprint
- Author
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Shaojun Fu, Liangjin Ge, Zhijun Zhang, Yanlin Liao, and Xudi Wang
- Subjects
Materials science ,business.industry ,Bilayer ,Substrate (electronics) ,Nanoimprint lithography ,law.invention ,Nanolithography ,Resist ,law ,UV curing ,Optoelectronics ,business ,Lithography ,Layer (electronics) - Abstract
We present results on the nanofabrication of high density patterns in SU-8 resist, based on nanoimprinting combined with UV curing. The bilayer process using PMMA as sacrificial layer was developed to release the SU-8 layer to form three dimensional structures. The SU-8 displays excellent imprint property and well defined patterns are achieved at at low temperature, low pressure after demolding process. Using this technology, 300nm period SU-8 subwavelengh gratings and nanochannels were fabricated on flat substrate with good fidelity. This sacrificial layer-assisted UV curing imprint technology offers versatility and flexibility to stack polymer layers and sealed fluidic channels. more...
- Published
- 2007
- Full Text
- View/download PDF
36. Design and fabrication of soft X-ray blazed diffraction gratings
- Author
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Ying Liu, Xin Tan, Shaojun Fu, Xiangdong Xu, and Yilin Hong
- Subjects
Diffraction ,Materials science ,Holographic grating ,business.industry ,Holography ,Physics::Optics ,Mach–Zehnder interferometer ,law.invention ,Optics ,law ,Angle of incidence (optics) ,Physics::Space Physics ,Blazed grating ,Physics::Atomic Physics ,business ,Diffraction grating ,Beam splitter - Abstract
Diffraction gratings are designed for grazing-incidence operation in the soft x-ray spectral region. The efficiencies for various diffraction orders are simulated as a function of angle of incidence and blazed angles. According to the beat phenomenon, the grating pattern with double-frequency on the same substrate is recorded in a holographic way. The blazed grating will be fabricated using holography and ion beam etching method. The primary experimental results are presented. This kind of blazed grating is a key element used as a beam splitter of soft x-ray Mach-Zehnder interferometer, which is a new tool to diagnose the plasma generated by the laser-based inertial confinement fusion. more...
- Published
- 2006
- Full Text
- View/download PDF
37. Design of variable-line-space plane gratings with holographic recording
- Author
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Ying Liu, Shiping He, Shaojun Fu, Xiangdong Xu, and Jun Lou
- Subjects
Wavefront ,Plane (geometry) ,business.industry ,Holography ,Physics::Optics ,Expression (mathematics) ,law.invention ,Optics ,law ,Genetic algorithm ,Line (geometry) ,business ,Position sensor ,Mathematics ,Variable (mathematics) - Abstract
Variable Line-Space gratings play an important role in focusing and aberration-reduced. They are widely used in spatial spectrum and synchrotron radiation facilities. However the design and fabrication methods of them are difficult. The problem is to be able to record holographically the expected grooves distribution. The geometric theory of aspheric wave-front recording optics is briefly described. We introduce the genetic algorithm to the parameters optimization of holographic variable line-space gratings. In order to obtain a steady set of recording parameters, we propose that the objective function of the genetic algorithm should consider the effect of the recording parameters errors. The integral expression of the objective function is also derived to improve the efficiency of calculation. Design example of holographic variable line-space plane gratings for a position sensor is given to demonstrate the capability of this method. The line-profiles of variable line-space plane gratings with different recording parameters are also compared in this paper. more...
- Published
- 2005
- Full Text
- View/download PDF
38. Studies on phase Ronchi gratings and the fabrication of soft x-ray condenser zone plates
- Author
-
Jun Lou, Ying Liu, Shaojun Fu, Kai Xiao, Xiangdong Xu, and Yilin Hong
- Subjects
Diffraction ,Materials science ,business.industry ,Condenser (optics) ,Zone plate ,law.invention ,Optics ,Etching (microfabrication) ,law ,X-ray lithography ,Photolithography ,business ,Lithography ,Beam splitter - Abstract
Ronchi gratings are widely used as beam splitters in interferometry. The phase Ronchi gratings are fabricated in K9 (or BK7) substrates using a photolithographic process and ion beam etching process. The geometry of the gratings was determined within the approximations of the scalar diffraction theory to minimize their diffraction intensities in 0 and 2 orders at 514.5nm. Their diffractive characteristics are measured using Ar+ laser at 514.5 and 496.5nm. The phase Ronchi gratings exhibit the diffraction intensity in 0 or 2 order to be three orders of magnitude less than that in 1 order. Soft x-ray condenser zone plates are one of the most essential condensing and dispersing elements in the field of soft x-ray microscopy. The zone-plates are used at 3.2nm, whose diameters are 2.8mm. The widths of their outermost zone are 647nm. The zone plate is made of Au. Self-supporting zone plates are fabricated by holography-ion beam etching process to obtain x-ray lithography mask, the x-ray lithography, photolithography and micro electroplating process were used to obtain their self-supporting structure. The self-supporting zone plates are free of membrane absorption and degradation. more...
- Published
- 2005
- Full Text
- View/download PDF
39. Reactive ion beam etching of HfO 2 film using Ar/CHF 3 gas chemistries
- Author
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Yiling Hong, Xiangdong Xu, Xudi Wang, Shaojun Fu, and Ying Liu
- Subjects
Argon ,Materials science ,Ion beam ,chemistry ,Etching (microfabrication) ,Reactive ion beam etching ,Analytical chemistry ,chemistry.chemical_element ,Plasma ,Dielectric ,Photoresist ,Selectivity - Abstract
A number of current and future optical and optoelectronic devices require the creation of structure in HfO 2 film. The reactive ion beam etching of HfO 2 film and photoresist mask in Ar/CHF 3 gas mixture was examined as a function of ion energy, discharge composition and ion beam incident angle. The details of etch rate have been interpreted in terms of mechanism of etching. The etch rate has shown a square root dependence on ion energy and variation versus incidence angle. The CHF 3 - plasma produced some chemical enhancement in HfO 2 film etching. Compared with pure argon etching, better selectivity and higher fidelity pattern transfer were achieved with Ar/CHF 3 for HfO 2 film over photoresisit mask. The AFM scans of etched HfO 2 film by tapping mode showed good surface quality. Key words: Reactive ion beam etching; HfO 2 film; etch rate; etch selectivity; fidelity pattern transfer; surface quality 1. Introduction HfO 2 film has high dielectric constants and is thermally stable material, which has been considered to be promising candidate to replace SiO more...
- Published
- 2005
- Full Text
- View/download PDF
40. VUV and soft x-ray diffraction grating fabrication by holographic ion beam etching
- Author
-
Yilin Hong, Xiangdong Xu, and Shaojun Fu
- Subjects
Materials science ,Holographic grating ,Spectrometer ,business.industry ,Holography ,Grating ,law.invention ,Optics ,Beamline ,law ,Etching (microfabrication) ,Blazed grating ,business ,Diffraction grating - Abstract
Holographic and ion beam etching technique has become routine means for fabricating vacuum ultraviolet and soft x-ray diffraction gratings. A novel technique has been successfully, in which oxygen reactive ions etching was used to achieve resist ashing of the grating, to fabricate diffraction gratings with holographic ion beam etching. The new technique was used to fabricate a spherical blazed grating, 1200g/mm and 130 nm blazed wavelength, and some laminar gratings for monochromators in the beamline of National Synchrotron Radiation Laboratory. The results show that the new technique can considerably lower the stringent requirements of holographic exposure and development, and makes it controllable to make smooth grooves with desirable depth and duty cycle. A gold transmission grating is one of the critical elements in the soft x-ray spectrometer for plasma diagnostics. With holographic-ion beam etching technique, a number of self-supporting transmission gratings have been fabricated for inertial confinement fusion (ICF) diagnosis. more...
- Published
- 2005
- Full Text
- View/download PDF
41. Fabrication of varied-line-space grating by elastic optics
- Author
-
Shaojun Fu, Yongjun Xie, and Shiping He
- Subjects
Fabrication ,Materials science ,Optics ,business.industry ,Line (geometry) ,Physics::Optics ,Optoelectronics ,Grating ,Space (mathematics) ,business ,Lithography ,Position sensor ,Interference lithography - Abstract
We demonstrate a method to fabricate varied-line-spacing grating by employing elastic medium with variable vertical section. The advantages of this technique include continuous diversity of variation of line-space, high fabrication efficiency and low cost, etc. It is very difficult or unrealizable to produce this variation of line-space by traditional interference lithography. This kind of grating can be used in the optical position sensor and it can improve the precision of the sensor. more...
- Published
- 2005
- Full Text
- View/download PDF
42. Electromagnetic analysis of diffractive lens with C method and local linear grating model
- Author
-
Ying Liu, Kai Xiao, and Shaojun Fu
- Subjects
Diffraction ,Physics ,Wavelength ,Optics ,Diffractive lens ,Local linear ,business.industry ,Coordinate system ,Physics::Optics ,Grating ,Polarization (waves) ,business ,Diffraction efficiency - Abstract
The electromagnetic theory should be applied to determine the diffraction efficiency of structures whose minimum line width is comparable with wavelength or the grooves are too deep, where scalar theory is no longer useful. The coordinate transformation method (the C method) is a very efficient method for obtaining continuous surface-relief grating efficiency for both TE and TM polarization. The local linear grating model (LLGM) models 2-D circular diffractive lens with combination of a series of local linear gratings. We synthesized and analyzed circular diffractive lens with a continuous profile not as previous authors who always use multi-lever structures. The result is compared with that of scalar theory and analysis using LLGM and rigorous coupled-wave theory. This optimization can be used as a complement of the scalar design of diffractive lens. more...
- Published
- 2005
- Full Text
- View/download PDF
43. Precise design of the pure phase element for quasi-annular beam shaping
- Author
-
Yiqiong Zhao, Yuan Wu, Junzhong Xu, Yong-Ping Li, and Shaojun Fu
- Subjects
Physics ,Diffraction ,symbols.namesake ,Fourier transform ,Cardinal point ,symbols ,Phase (waves) ,Mode (statistics) ,Design process ,Sampling (statistics) ,Invariant (mathematics) ,Topology - Abstract
The phase distribution design process of the pure phase element (PPE) used for quasi-annular beam shaping is introduced in this paper. A new optimization algorithm named Quasi-Gradient Descent (Quasi-GD) algorithm has been developed and used here to meet such design requirement. With a more restrictive sampling mode named precise sampling in the optimization, the simulated result shows that the uniformity of energy distribution on the focal plane is invariant with different sampling intervals and the true beam shaping effect is achieved. more...
- Published
- 2002
- Full Text
- View/download PDF
44. Fabrication of self-supporting transmission gratings for plasma diagnostics
- Author
-
Yangchao Tian, Yilin Hong, Xiangdong Xu, Shiping Jiang, Tonglin Huo, Xiaoming Tao, Shaojun Fu, and Hongjun Zhou
- Subjects
Materials science ,business.industry ,Detector ,Physics::Optics ,Grating ,Photoresist ,Laser ,Computer Science::Other ,law.invention ,Optics ,Resist ,law ,Etching (microfabrication) ,business ,Diffraction grating ,Inertial confinement fusion - Abstract
With holographic-ion beam etching technique, a number of self-supporting transmission gratings have been fabricated for inertial confinement fusion diagnosis. In addition to the general process, a practical method for monitoring the evolution of the grating structures exposed in photoresist during development of the resist. The real-time monitor technique developed here is relatively simple in comparison with a He-Ne laser and detector, which needs delicate control. more...
- Published
- 1999
- Full Text
- View/download PDF
45. Fabrication and performance of etched multilayer x-ray optics
- Author
-
Zhanshan Wang, Xingdan Chen, Xiangdong Xu, Shaojun Fu, Yueying Ma, Yilin Hong, and Jianlin Cao
- Subjects
Optics ,Fabrication ,Materials science ,Resist ,Multilayer soft lithography ,business.industry ,Etching (microfabrication) ,X-ray optics ,Sputter deposition ,business ,Diffraction grating ,Diffractometer - Abstract
We present the recent advances achieved in the Changchun Institute of Optics and Fine Mechanics, Chinese Academy of Science, in the field of the soft X-ray etched multilayer optics. In the present study, Mo and Si have been chosen as materials for the scattering layer and space layer soft X-ray multilayer, respectively. The fabrication of Mo/Si multilayer used by the magnetron sputtering, the patterned resist was obtained by optical holography, and the pattern of the resist was transferred into the multilayer by the ion beam etching. The several components based on soft X-ray etched multilayer were measured by grazing incidence X-ray reflectance measurements at (lambda) equals 0.154 nm (Cu-K (alpha )) using a conventional diffractometer. more...
- Published
- 1998
- Full Text
- View/download PDF
46. Microtribiology and self-lubrication microsystems
- Author
-
Yiguan Hu, Yilin Hong, Gang Liu, Shaojun Fu, and Yangchao Tian
- Subjects
Microelectromechanical systems ,Materials science ,Precision engineering ,Microsystem ,Microfluidics ,Surface force ,Electroforming ,Lubrication ,Nanotechnology ,Tribology ,Composite material - Abstract
The microtribology phenomena on the micro contact( or slide ) surface, where the effects of surface forces are more significant than those of gravity, is very different with the conventional machine. The friction force that works on a friction face of a microsystems is significantly high relative to the size of the machine, the fluid lubrication in the conventional size mechanical parts cannot reduce the friction force on the microsystems, the solid lubrication (self-lubrication) should be applied to reduce the friction force. In this paper, the solid lubrication MoS 2 was studied. MoS 2 is embedded into the Ni structure in electroforming process. The results show that MoS 2 can be used as the solid lubrication in the microsystem to reduce the friction force and enhance the hardness of microsystem. more...
- Published
- 1998
- Full Text
- View/download PDF
47. Manufacturing technology by synchrotron radiation in NSRL
- Author
-
Yiguan Hu, Dapeng Chen, Xiaoming Tao, Yilin Hong, Shaojun Fu, Andong Xia, Gang Liu, Yangchao Tian, Ya Kan, and Xinyi Zhang
- Subjects
Fabrication ,Materials science ,business.industry ,Condenser (optics) ,Synchrotron radiation ,Zone plate ,law.invention ,Optics ,law ,Optoelectronics ,X-ray lithography ,business ,LIGA ,Lithography ,Diffraction grating - Abstract
In this paper a brief description is given to introduce the activities of the manufacturing technology using the synchrotron radiation light source in the National Synchrotron Radiation Laboratory (NSRL). The light source in NSRL is a dedicated synchrotron radiation facility in China. Five beamlines and corresponding experimental stations, including soft x-ray lithography, have been constructed. The main experimental results obtained from the soft x-ray lithography station are reported. We have fabricated some devices using the synchrotron radiation lithography, for example, the high electron mobility transistor, high T c superconductor infrared detector-array, diffraction grating, and micro condenser zone plate. A simple method for the achievement of synchrotron radiation x-ray lithography mask will also be presented. The LIGA (German abbreviation for: Lithograpie, Galvanoforming, and Abforming) technique has been developed in NSRL. It is the most promising technique for the fabrication of three-dimensional microstructures. We are successful in making several microdevices by deep x-ray lithography and microelectroforming, such as microgearwheel, micro acceleration sensor. more...
- Published
- 1998
- Full Text
- View/download PDF
48. Special Ronchi grating as the shearing element of shearing ESPI for nondestructive testing
- Author
-
Xiaoping Wu, Shaojun Fu, and Lin-yong Pang
- Subjects
Diffraction ,Engineering ,Speckle pattern ,Interferometry ,Optics ,Shearography ,business.industry ,Nondestructive testing ,Grating ,business ,Diffraction grating ,Shearing (manufacturing) - Abstract
A new electronic shearing speckle pattern interferometry using a special Ronchi grating as the shearing element has been developed and applied to deformation measurement and non destructive testing (NDT) in the practical environment. This special designed Ronchi grating is a kind of phase grating. It can make zero order and all even order beams disappear and among all odd order beams the +/- 1 order beams are much stronger than others. This new shearing element has many advantages, such as small volume, light weight, lower price, lower energy lost and good quality of shearing image. The experimental results show that it is good at electronic shearography. more...
- Published
- 1997
- Full Text
- View/download PDF
49. Development Of High Resolution Zone Plate By Holography And Ion-Etching Techniques
- Author
-
Yun-Wu Zhang, Xiao-Min Tao, Shaojun Fu, Yong-Gang Su, and Yilin Hong
- Subjects
Optics ,Materials science ,business.industry ,Etching (microfabrication) ,law ,technology, industry, and agriculture ,Holography ,High resolution ,Development (differential geometry) ,Zone plate ,business ,law.invention ,Ion - Abstract
The purpose of development and the processing steps to fabricate high resolution zone plates, especially holographic exposure and ion-etching, are described. Also the experimental results and some prospects are presented. more...
- Published
- 1988
- Full Text
- View/download PDF
50. A Holographic Match Filtering Method With High Diffraction Efficiency
- Author
-
Yonggang Su, Guoguang Yang, and Shaojun Fu
- Subjects
Diffraction ,Engineering ,business.industry ,Dynamic range ,Matched filter ,Holography ,Phase (waves) ,Diffraction efficiency ,law.invention ,symbols.namesake ,Fourier transform ,Optics ,law ,symbols ,business ,Phase matching - Abstract
From physical analysis, we explained that the phase matching is more important than the amplitute in match filtering. Thus the amplitute of Fourier transform of object can be modified to reduce the dynamic range, while the phase information keeps unchanging. The holographic match filter was made by dichromatic gelatin. High efficiency correlation can be obtained by this method. more...
- Published
- 1988
- Full Text
- View/download PDF
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