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《中国光学快报(英文版)》2016,(5)
A method of multi-beam femtosecond laser irradiation combined with modified HF-HNO_3-CH_3 COOH etching is used for the parallel fabrication of all-silicon plano-concave microlens arrays(MLAs). The laser beam is split by a diffractive optical element and focused by a lens to drill microholes parallely on silicon. An HF-HNO_3-H_2SO_4-CH_3 COOH solution is used to expand and polish laser-ablated microholes to form microlenses. Compared with the HF-HNO_3-CH_3 COOH solution,the solution with H_2SO_4 can effectively reduce the etched surface roughness. The morphologies of MLAs at different laser powers and pulse numbers are observed. The image array formed by the silicon microlenses is also demonstrated. 相似文献
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大数值孔径衍射透镜的优化设计方法 总被引:4,自引:0,他引:4
本文针对大数值孔径衍射透镜工艺制作难的问题,以菲涅耳衍射透镜为例,研究了相位匹配原理并提出了一种优化设计二元大数值孔径衍射透镜的方法。在菲涅耳衍射透镜原理的基础上,确定了优化设计多相位台阶衍射透镜的结构参数,并给出了一个设计实例,最后对结果元件的衍射效率进行了分析与讨论。 相似文献
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Multilevel diffractive microlens fabrication by one-step laser-assisted chemical etching upon high-energy-beam sensitive glass 总被引:2,自引:0,他引:2
A new technique of laser-assisted single-step chemical etching for diffractive microlens fabrication upon high-energy-beam sensitive glass is reported. Laser direct writing with calibrated writing parameters results in gray-level mask patterns upon the ion-exchanged layer of the glass. The transmittance-dependent chemical etching upon the glass is then effectively utilized to yield suitable surface relief structures for multiple-phase-level diffractive optical elements. The one-step nonphotolithographic fabrication technique has been successfully applied for the realization of an eight-phase-level diffractive microlens. 相似文献
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Zhongke Wang Koji Sugioka Katsumi Midorikawa 《Applied Physics A: Materials Science & Processing》2007,89(4):951-955
We report the three-dimensional (3D) integration of microoptical components such as microlenses, micromirrors and optical
waveguides in a single glass chip by femtosecond (fs) laser direct writing. First, two types of microoptical lenses were fabricated
inside photosensitive Foturan glass by forming hollow microstructures using fs laser direct writing followed by thermal treatment,
successive wet etching and additional annealing. One type of lens is the cylindrical microlens with a curvature radius R of
1.0 mm, and the other is the plano-convex microlens with radius R of 0.75 mm. Subsequently, by the continuous procedure of
hollow microstructure fabrication, a micromirror was integrated with the plano-convex microlens in the single glass chip.
Further integration of waveguides was performed by internal refractive index modification using fs laser direct writing after
the hollow structure fabrication of the microlens and the micromirror. A demonstration of the laser beam transmission in the
integrated optical microdevice shows that the 3D integration of waveguides with a micromirror and a microoptical lens in a
single glass chip is highly effective for light beam guiding and focusing.
PACS 42.62.-b; 81.05.Kf; 42.82.Cr; 82.50.Pt; 42.79.Gn 相似文献
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在分析单层和多层衍射元件衍射效率的基础上,推导出光学系统中多层衍射元件浮雕深度和基底材料的一般关系式,并对这些变量进行优化,得到阿贝数的值大致在20~80之间,β的合理值在0.25~0.6之间,当2个衍射元件的阿贝数v1<v2,且差值比较大时,阿贝数小的衍射元件的基底材料选择光学玻璃中的火石玻璃,阿贝数大的衍射元件的基底材料选择光学玻璃中的冕牌玻璃。根据这个方法,设计了3组可实现宽波段高衍射效率的不同材料、不同浮雕深度的组合,使得每组组合中两层衍射元件的衍射效率都在99%以上。 相似文献
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《中国光学快报(英文版)》2016,(12)
The demand for space-borne telescopes with an aperture of 20 m is forcing the development of large diameter diffractive Fresnel zone lenses(FZLs) on membranes. However, due to the fabrication errors of multi-level microstructures, the real diffraction efficiency is always significantly smaller than the theoretical value. In this Letter,the effects of a set of fabrication errors on the diffraction efficiency for a diffractive membrane are studied. In order to verify the proposed models, a 4-level membrane FZL with a diameter of 320 mm is fabricated. The fabrication errors of the membrane FZL are measured, and its diffraction efficiency in the +1 order is also tested.The results show that the tested diffraction efficiency is very close to the calculated value based on the proposed models. It is expected that the present work could play a theoretical guiding role in the future development of space-borne diffractive telescopes. 相似文献
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为了提高激光直写加工衍射光学元件时的线条质量,提出一种离焦激光直写的线宽稳定方法.该方法通过同时调节激光功率和离焦量,使光刻胶的曝光阈值处于线宽对曝光量的变化率较小位置,从而可以弱化线宽对实际曝光量或光刻胶阈值等变化的敏感度,提高利用离焦方法进行衍射光学元件制作时的线宽稳定性.推导了稳定线宽后的光功率控制模型和线宽模型,模型中的变量仅为离焦量,降低了光功率控制的复杂性.利用632.8 nm的He-Ne激光和NA-0.1的物镜在CCD上对采用该方法后的离焦线宽模型进行验证,实验结果与理论模型吻合较好.该方法对于线宽稳定度较高的衍射光学元件制作具有重要价值. 相似文献
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Three-dimensional focus shaping with cylindrical vector beams 总被引:1,自引:0,他引:1
A three-dimensional focus shaping technique using the combination of cylindrical polarization with binary diffractive optical element is proposed. The energy density pattern at the vicinity of the focus can be tailored in three dimensions by appropriately adjusting the parameters of the cylindrical vector beam illumination, numerical aperture of the objective lens and the design of the binary diffractive optical element. Focus with extended depth of focus that has both transversal and longitudinal flattop profile is obtained. Optical bubble that has a total dark volume surrounded by high field distributions is also shown. Potential applications of this focus shaping technique are discussed. 相似文献
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Chia-Hung Hou Ming-Hung Li Chii-Chang Chen Jenq-Yang Chang Jinn-Kong Sheu Gou-Chung Chi Chuck Wu Wei-Tai Cheng Jui-Hung Yeh 《Optical Review》2003,10(4):287-289
In this work, diffractive microlenses were fabricated in GaN using a gray-level mask and inductively coupled plasma etching technique. We also propose to insert the GaN/AIN band- pass filter in the microlenses to enhance the ultraviolet/visible rejection ratio. Due to high transparency of GaN and AIN in UV, the microlenses can potentially be used in a UV micro-optics system such as for solar-blind detection. In the design example of this work, the structure may enhance the ultaviolet/visible rejection to 102. 相似文献
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A. Emoto A. Tashima M. Kondo M. Okada S. Matsui N. Kawatsuki H. Ono 《Applied physics. B, Lasers and optics》2012,107(3):741-748
Anisotropic diffractive gratings formed by birefringent molecular alignment are fabricated by a holographic technique using a photo-cross-linkable liquid crystalline copolymer (PLCCP). Depending on the exposure energy used for holographic recording, bright or dark regions of the interference fringe can be chosen for the molecular-aligned region, analogous to positive- and negative-type photoresist processing in photolithography. In conjunction with simultaneously generated surface relief gratings, the anisotropic refractive index modulation inherent in the PLCCP film exhibits different diffraction properties depending on the incident beam polarization. The anisotropic refractive index grating profiles are quantitatively presented for two cases determined by the exposure energy, based on the Fourier analysis of diffractive optics. The selection of different grating formations selected by varying only the exposure energy could provide a strategy for the fabrication of functionalized diffractive optical elements. 相似文献
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S.H. Ghasemi M.R. HantehzadehJ. Sabbaghzadeh D. DorranianV. Vatani A. BabazadehK. Hejaz A. HemmatiM. Lafouti 《Optics and Lasers in Engineering》2012,50(2):293-296
A plano-convex aspheric lens is designed to collimate the emitted light of the fiber optics. In this paper even orders of general aspheres are used to describe the aspheric surfaces sag. To determine the aspheric coefficient, the even asphere polynomial are fitted on the computed sag data. The surface sag data is determined using genetic algorithm method. The surface sag was analyzed by the commercial optical software package ZEMAX. For typical fiber optics, the numerical aperture (NA) of 0.22 was assumed. With this specification, the expected output spot diagram of 20 mm and the maximum aperture of 25.4 mm have been obtained. A comparison between here presented lens and the similar type of conventional lens has been carried out; the proposed aspheric lens corrected the spherical aberration, which led to increase in the collimated distance. 相似文献
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We report a laser writing system for fabrication of diffractive optical elements with He-Cd laser. The wavelength of the light source is 441.6 nm. The output beam is collimated into parallel light with uniform intensity distribution after passing through the spatial filter with a pinhole of 25μm and the collimating device. A microscopy objective lens with numerical aperture (NA) of 0.65 is used to focus the beam into a small diffraction spot. Any pattern can be written with this system. Experimental results are presented.The written gratings and the phase patterns were verified with a conventional optical microscopy and the Taylor Hobson equipment. 相似文献
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针对目前二元光学元件掩模制作工艺过程的诸多不足,对连续型平面衍射聚光透镜掩模的激光直写制作工艺进行了研究。基于基尔霍夫标量衍射理论,采用光线追迹法设计了连续型平面衍射聚光透镜掩模。采用激光直写技术,利用CLWS 300M/C极坐标激光直写设备、S1830光刻胶和MICROPOSIT 351显影液,进行了刻写实验。实验表明,激光能量、预烘烤温度、显影液浓度以及预曝光对掩模微结构的制作均有影响。最后制作了掩模。与二元光学元件掩模的制作工艺相比,该技术具有工艺简单、制作周期短且易于操作的优点。 相似文献
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《Journal of Physics and Chemistry of Solids》2007,68(5-6):916-919
Direct laser writing with high power densities at a wavelength of 244 nm is applied to the patterning of surface relief diffractive optical elements (DOEs) with submicron features in thin chalcogenide layers of different compositions. The topology of created features in dependence on exposure conditions is investigated. Potential and limitations of this technique for the fabrication of efficient DOEs for applications from the visible to the near infrared spectral region are discussed on the basis of examples. 相似文献