共查询到20条相似文献,搜索用时 31 毫秒
1.
M. Tang M. H. Hong Y. S. Choo Z. Tang Daniel H. C. Chua 《Applied Physics A: Materials Science & Processing》2010,101(3):503-508
In this work, super-hydrophobic surfaces were fabricated by femtosecond laser micro-machining and chemical vapor deposition
to constitute hybrid scale micro/nano-structures formed by carbon nanotube (CNT) clusters. Nickel thin-film microstructures,
functioning as CNT growth catalyst, precisely control the distribution of the CNT clusters. To obtain minimal heat-affected
zones, femtosecond laser was used to trim the nickel thin-film coating. Plasma treatment was subsequently carried out to enhance
the lotus-leaf effect. The wetting property of the CNT surface is improved from hydrophilicity to super-hydrophobicity at
an advancing contact angle of 161 degrees. The dynamic water drop impacting test further confirms its enhanced water-repellent
property. Meanwhile, this super-hydrophobic surface exhibits excellent transparency with quartz as the substrate. This hybrid
fabrication technique can achieve super-hydrophobic surfaces over a large area, which has potential applications as self-cleaning
windows for vehicles, solar cells and high-rise buildings. 相似文献
2.
衍射光学元件较球面、非球面光学元件在校正色差方面具备较大优势,尤其是在红外光学领域,应用衍射光学元件可进一步增加光学系统的设计自由度。随着红外光学市场的进一步增大,常规的衍射光学金刚石车削技术难以满足大规模需求,精密模压技术成为解决上述问题的关键技术。模具设计是实现精密模压的重点,为了缩减模具设计周期,该文采用有限元仿真方法对模具进行预先设计及补偿,并试加工。采用单站式精密模压机对设计的模具进行了精密模压试验。模压试验结果表明:采用合理的工艺参数,能够实现衍射光学元件面形精度PV达到0.56μm,位置误差<0.011 mm,环带高度误差<0.12μm,验证了仿真预先补偿在衍射光学模具设计中的有效性。 相似文献
3.
A valid method for measuring the large-aperture convex surface by using a curved diffractive optical element (DOE) and a Zygo interferometer is demonstrated experimentally. In this method, the direct use of source and high-resolution CCD camera of Zygo interferometer represents a major advance in the areas of adjustment. The DOE, fabricated by combining laser direct writing and lithography, results in higher accuracy, efficiency and lower cost for testing aspheric compared with other types of DOE employed. We have fabricated one optical test system and measured a 110-mm-diameter convex surface of errors 44.3 nm rms and 311 nm P–V. 相似文献
4.
We demonstrate a compact optical correlator using a diffractive optical element (DOE) beam splitter for 2D optical image processing. Image frequency conversion and correlation are demonstrated using third-harmonic generation (THG) in an organic film with a 1550 nm femtosecond laser. Spatial and temporal alignment of the femtosecond pulses are obtained by imaging the DOE onto the organic film. 相似文献
5.
Bo YinLiang Fang An-qiong TangQiu-liu Huang Jia HuJian-hui Mao Ge BaiHuan Bai 《Applied Surface Science》2011,258(1):580-585
A novel super-hydrophobic coating was prepared by chemical modification on the anodized aluminum alloy surface. The surface structure was characterized by water contact angle measurement, scanning electron microscopy (SEM), and the composition was measured by X-ray photoelectron spectroscopy (XPS). The corrosion behavior of the super-hydrophobic coating was evaluated by the polarization curve and the electrochemical impedance spectroscopy (EIS). It was found that the static water contact angle on the surface of super-hydrophobic coating was as high as 167.7 ± 1.2°, and the sliding angle was 5°. The super-hydrophobic coating resulted in excellent corrosion resistance property and the super-hydrophobic coating showed a good stability. 相似文献
6.
A computer aided engineering (CAE) tool-assisted technique, using Moldex3D and aspheric analysis utility (AAU) software in
a polycarbonate injection molding design, is proposed to manufacture large diameter aspheric plastic lenses. An experiment
is conducted to verify the applicability/feasibility of the proposed technique. Using the preceding two software tools, these
crucial process parameters associated with the surface profile errors and birefringence of a molded lens can be attainable.
The strategy adopted here is to use the actual quantity of shrinkage after an injection molding trial of an aspherical plastic
lens as a reference to perform the core shaping job while keeping the coefficients of aspheric surface, radius, and conic
constant unchanged. The design philosophy is characterized by using the CAE tool as a guideline to pursue the best symmetry
condition, followed by injection molding trials, to accelerate a product’s developmental time. The advantages are less design
complexity and shorter developmental time for a product. 相似文献
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Ana Menéndez-Manjón Andreas Schwenke Timo Steinke Matthias Meyer Ulrich Giese Philipp Wagener Stephan Barcikowski 《Applied Physics A: Materials Science & Processing》2013,110(2):343-350
Polymer matrix nanocomposites filled with metallic and alloy nanoparticles add functionality in various applications such as optical devices and in the energy sector. However, matrix coupling agents or nanoparticle ligands may be unwanted additives, potentially inhibiting the resulting nanocomposite to be processed by injection molding. The generation of stabilizer-free Au, Ag, and AuAg alloy nanoparticle acrylate composites is achieved by picosecond-pulsed laser ablation of the respective metal target in the liquid monomer. Complementary to laser ablation of the solid alloy, we have alloyed nanoparticles by post-irradiation of Au and Ag colloids in the liquid monomer. The optical properties of the colloidal nanoparticles are successfully transferred to the solid poly(methyl methacrylate) matrix and characterized by their plasmon resonance that can be easily tuned between 400 and 600 nm by laser alloying in the liquid monomer. 相似文献
10.
A diffractive optical element (DOE) is applied to effectively locate a laser pointer spot on a projection screen for laser pointer interaction applications. The DOE is placed in front of a digital web camera to blur the background image while transforming the laser spot into a large diffractive pattern, such as a circle. To calculate the diffractive pattern position on the screen, only a simple subtraction method using two successive digital images with the laser ON and OFF, respectively, is needed. This approach also improves the compressed digital image transmission latency. 相似文献
11.
The preparation of super-hydrophobic metal surfaces had to combine rough structures and the surface modifications with low surface energy materials. Although there were different views on it, no experiment was done to prove it yet. In this paper, the structure of natural lotus leaf was observed and the lotus-like surfaces on hydrophilic copper substrates were fabricated via electroplating in large current density. These surfaces were super-hydrophobic without any chemical modification. The hydrophobic mechanism was analyzed. It is believed that this was a meta-stable state in Cassie model. As long as the surface structure was suitable, hydrophobic surface, even super-hydrophobic surface, could be got on hydrophilic substrate. 相似文献
12.
Fong-Zhi Chen Cheng-Huan Chen Cheng-Hsien Wu Ching-Hsiang Kuo Jyh-Rou Sze Wei-Yao Hsu Yuan-Chieh Cheng 《Optical Review》2012,19(4):238-241
This paper introduces the development of a double-sided micro lens array (DSMLA) for application in micro laser projectors. For commercial mass production, it is necessary to investigate the concurrent engineering of optical design, mold fabrication, and plastic injection molding at once. This experiment based the design of the micro lens array on the scalar diffraction theory. The proposed DSMLA can simultaneously shape red, green, and blue laser beams into a uniform projection pattern. An ultra precision diamond turning machine using a slow tool servo method fabricated the mold. The study considered optical design constraints from the feedback of mold fabrication and plastic injection molding, measuring and comparing fabricated samples with calculated results. Experimental results show that the fabricated DSMLAs achieve the desired function and application feasibility for micro laser projectors. 相似文献
13.
The super-hydrophobic coating was successfully fabricated on the surface of magnesium alloy AZ31 by chemical etching and surface modification. The surface morphologies, compositions, wettability and corrosion resistance of the coating were investigated with SEM, XPS, contact angle measurement and electrochemical method, respectively. It shows that the rough and porous micro-nano-structure was presented on the surface of magnesium alloy, and the contact angle could reach up to 157.3 ± 0.5° with sliding angle smaller than 10°. The super-hydrophobic coating showed a long service life. The results of electrochemical measurements showed that anticorrosion property of magnesium alloy was improved. The super-hydrophobic phenomenon of the prepared surface was analyzed with Cassie theory, and it finds that only about 10% of the water surface is contacted with the metal substrate and the rest 90% is contacted with the air cushion. 相似文献
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Takahiro Kurashima Koichi Sakuma Takayuki Arai Akihiro Tagaya Yasuhiro Koike 《Optical Review》2012,19(6):415-418
We have demonstrated a polarized laser backlight for liquid crystal displays and have investigated its basic polarization properties. To maintain the state of polarization of light propagating through the light-guide plate (LGP) of the backlight, we fabricated the LGP by injection molding of a zero-zero-birefringence polymer, poly(methyl methacrylate-co-2,2,2-trifluoroethyl methacrylate-co-benzyl methacrylate) (52: 42: 6 by mass) that is free of both orientational and photoelastic birefringence. The degree of polarization of light from the resulting backlight (average: 92.4%) was much higher than that from a backlight with a polycarbonate LGP (average: 8.0%) in the defined effective range of the backlight. A laser speckle pattern was observed but the speckle contrast on the output surface of the backlight was reduced from 68 to 10% by vibrating a diffuser sheet situated in front of the output surface of the LGP. We also manufactured a white surface light source [chromaticity (value: x, y) = (0:310, 0:314)] by mixing the outputs from three primary-color-emitting lasers in the backlight. 相似文献
16.
Cheung EC Ho JG Goodno GD Rice RR Rothenberg J Thielen P Weber M Wickham M 《Optics letters》2008,33(4):354-356
A diffractive optical element (DOE) is used as a beam combiner for an actively phase-locked array of fiber lasers. Use of a DOE eliminates the far-field sidelobes and the accompanying loss of beam quality typically observed in tiled coherent laser arrays. Using this technique, we demonstrated coherent combination of five fiber lasers with 91% efficiency and M2=1.04. Combination efficiency and phase locking is robust even with large amplitude and phase fluctuations on the input laser array elements. Calculations and power handling measurements suggest that this approach can scale to both high channel counts and high powers. 相似文献
17.
A smart scheme for chaotic signal generation in a semiconductor ring laser (SRL) with optical feedback is proposed and investigated numerically. The chaotic oscillation in the SRL can be generated by the partial reflection of the laser output. Time series, attracter and the power spectrum, as well as the Lyapunov exponent spectrum, are calculated and analyzed. We also study the synchronization scheme of feedback-induced chaos in SRLs by optical injection that consists of a drive SRL with optical feedback and a response SRL with optical injection from the drive laser. High-quality synchronization is achieved with suitable injection strength and detuning frequency between the drive and the response SRLs. 相似文献
18.
CAE在塑料光学零件注射成型中的应用 总被引:2,自引:0,他引:2
目前光学塑料非球面零件在各种光电仪器中的应用越来越普遍。针对在注射成型光学塑料零件时对质量的特殊要求,本文介绍了利用注射成型CAE(computer aidedengineering)软件Moldflow,通过对塑料填充过程、保压过程和冷却过程的模拟分析,对在成型中各工艺参数和模具结构影响光学塑料零件的残余应力和收缩率等最终质量问题进行了研究。从工艺参数的选取和模具结构设计等方面,提出了如何改善成型光学塑料零件质量的措施,给出了模具面形成型前补偿的方法。通过采用最大实体原则,利用Moldflow分析结果进行模具面形补偿最优化计算。 相似文献
19.
In this paper, the surface acoustic wave velocity results acquired from the inspection of specially manufactured and characterised alumina ceramic materials are presented. Ultrasonic velocity data of alumina-based ceramics in the range 60-100% theoretical density was generated utilising non-contacting laser-ultrasonic measurements based on laser generation and detection of surface acoustic waves with the objective of creating a routine technique for industrial advanced alumina inspection. With linear fitting the surface acoustic wave velocity data serves as a calibration graph for using laser ultrasonics for routine monitoring of alumina. A second laser ultrasonic technique based on the laser generation and foil transducer detection of surface acoustic waves was used to validate the surface acoustic wave velocities measured by the laser generation/detection technique. 相似文献
20.
Two chaos generation schemes are demonstrated numerically based on a semiconductor ring laser (SRL) with either a constant or a chaotic optical injection from an external distributed feedback (DFB) laser. Under a certain bias current, the chaotic output can be generated by the SRL with appropriate injection parameters. Parameter map is achieved numerically to show types of oscillation in the SRL. Bifurcation diagrams and Lyapunov exponent spectra roughly describe the routes to chaos for the SRL with disturbance. A bandwidth-enhanced chaos generation can be describes based on the chaotic optical injection scheme. The bandwidth of the bandwidth-enhanced chaos generated is about 12 GHz, which achieves approximately a two-fold increase compared with the constant injection scheme. 相似文献