共查询到20条相似文献,搜索用时 125 毫秒
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为确定卷积效应以及深度制作误差对小F数连续浮雕衍射透镜(DOE)轴向聚焦特性影响,基于瑞利-索末菲衍射理论建立了激光直写制作的连续浮雕衍射透镜非旁轴近似轴向光强分布模型.该模型考虑了连续浮雕衍射透镜的轴向衍射聚焦特性与透镜结构参数、写入光斑尺寸和扫描间距以及深度制作误差的关系,克服了傍轴近似条件下传统模型的不精确性.为验证模型的正确性,用激光直写制作了设计波长为441.6 nm,F数为4以及相位匹配因子为3的连续浮雕衍射透镜,并测试了波长441.6 nm激光入射时透镜的轴向聚焦特性.实验与分析表明,该模型分析结果与实验测试结果符合,从而证实模型的有效性,为激光直写制作的小F数连续浮雕衍射透镜的应用提供了理论依据. 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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研究了一种用于并行激光直写的连续深浮雕衍射透镜阵列方法.该方法采用连续浮雕衍射透镜阵列替换传统并行激光直写中的物镜阵列,在兼顾系统分辨力基础上,克服了波带片等衍射透镜阵列衍射效率低的缺点|同时因采用深浮雕结构优化环带宽度,可降低阵列的制作难度.针对并行激光直写系统阵列F/#小的特点,在建立连续深浮雕衍射透镜阵列非旁轴近似聚焦模型基础上,设计、制作和测试了波长为441.6 nm,F/#为7.5的连续深浮雕衍射透镜阵阵列.测试结果表明:该阵列的衍射效率优于70%,远高于波带片阵列的40%. 相似文献
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In this work, convex diffractive microlenses are designed for fabrication in GaN-based material with a gray-level mask. The aspect ratios of the surface relief of plano-convex and double-convex microlenses for different numerical apertures are compared to reduce the fabrication difficulty. The results show that for the numerical aperture less than 0.6, the aspect ratio of the double-convex diffractive microlenses is around half of the plano-convex diffractive microlenses. For the numerical aperture higher than 0.6, the aspect ratio of the plano-convex diffractive microlenses is similar to the double-convex diffractive microlenses. The error of the surface relief of the microlens occurring during the fabrication process is also discussed. 相似文献
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l.IntroductionMicroopticselementshasacceptedsPecialinterestingforitsabilityofgeneratearbi-trarydiffractionwave-front.BinarymethodhasbeencommonlyusedtomakeMOE,thismethodisengagedseveralmasksandseveraltimesofetchingtoapproachacontinuousre-lief,averyhighaccuracyofa1ignmentisrequried,theprocessingiscomp1exandtimeconsuming.ThereareseveralotherwaystofabricateMoEwithcontinuousreIief.Oneisholcagraphicrecording,thismethodcanproduceMoEwithlarSearea,butthefataldefectisthelowerdiffractionefficiency.A… 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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E. F. Reznikova B. G. Goldenberg V. I. Kondratyev G. N. Kulipanov V. P. Korolkov R. K. Nasyrov 《Bulletin of the Russian Academy of Sciences: Physics》2013,77(2):111-115
The manufacturing of test diffractive refractive intraocular lenses is illustrated by means of LIGA (deep X-ray LIthography and GAlvanoplastics and polymer forming). Dynamic X-ray lithography used while rotating the substrate versus an X-ray mask fixed in a beam of synchrotron radiation (SR) yields smooth optical 3D surfaces with roughnesses of 10–30 nm rms in polymethylmethacrylate (PMMA) layers. The axisymmetric diffractive refractive profile of a lens is predetermined by the radial angular function of the X-ray mask topology. The quality of the optical surface is reproduced for the nickel master form, which is electroplated onto a gold layer atop the PMMA relief. The optical quality also remains high for replicated lenses synthesized in this manner during silicon polymerization. 相似文献
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Realizing a smaller or sharper diffractive center spot is a valuable research aim in soft X-ray focus and other related research applications. Fresnel zone plates (FZP) and photon sieves (PS) are often used to focus the X-rays or other wavelength light at present. Here, we show that combination of a super-resolution phase mask (SPM) and an FZP (or PS) as one diffractive optical element can realize a smaller or sharper diffractive center spot without significantly increasing the fabrication difficulty. All these diffractive phase elements can be applied to beam shaping, mask-less lithography, energy congregation in high power lasers, soft X-rays focus, and any other field that requires a smaller or sharper diffractive center spot. 相似文献
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We present the digital-division-mask technique for the first time to solve the problem of decline in transverse resolution, which is caused by using digital micro-mirror device (DMD) to make binary optical elements (BOEs). One high-frequency gray-tone mask can be divided into several low-frequency masks by fixed or variable low-frequency period sampling. And the superimposed lithography effect of these low-frequency masks in the spatial or temporal domain is the same as that of the original high-frequency gray-tone mask. The paper firstly analyzes the digital-division-mask technique in theory and describes the feasibility and advantages. Then taking the diffractive surface fabrication of refractive-diffractive hybrid lens as an example, we conclude that the digital-division-mask technique improves the edge sharpness of lithography pattern, and enhances the diffractive efficiency of BOEs by experiment. 相似文献
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针对传统接触式曝光过程中掩模版因自身重力产生形变从而引入不可忽视的线宽误差和位置误差的问题,提出了一种大口径石英基底衍射透镜的高精度制备方法.采用背面具有真空道的高平面度、高强度金属校正工装吸附在掩模版上,利用掩模版上下表面的压强差使其与工装高度贴合,确保掩模版的高平面度.待石英基底所有区域均与掩模版结构面紧密贴合后取下工装.完成接触式曝光和显影后,采用反应离子刻蚀技术对大口径石英基底进行刻蚀,最终得到高精度微纳米结构.经有限元分析,使用该校正工装后,掩模版的形变量由28.85μm减小为0.88μm.实验结果表明,采用该方法制备的口径430mm两台阶石英基底菲涅尔衍射透镜波像差优于1/25λ,平均衍射效率为38.24%,达到理论值的94.35%,具有良好的聚焦和光学成像效果. 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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Laser induced backside wet etching combined with the diffractive gray tone phase mask has been used for the fabrication of a micro-lens array with a single lens diameter of 1 mm and a micro-prism in quartz. The micro-lens array was tested as beam homogenizer for high power XeCl excimer laser yielding a clear improvement in the quality of the laser beam.The optimum fluence range for fabrication of micro-lenses by laser induced backside wet etching using 1.4 M pyrene in THF solution and 308 nm irradiation wavelength is 1-1.6 J/cm2. The etching mechanisms of LIBWE are based on a combination of pressure and temperature jumps at quartz-liquid interface. 相似文献