876 resultados para antireflective coatings


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通过对基底与膜层、膜层之间界面处非均匀性对增透膜增透性能影响的讨论,得到以下结论:在沉积初期,由于基底表面特性和沉积参数的波动,从而在基底与膜层之间产生过渡层,使增透性能减弱,对增透膜的增透效果影响较大;在膜层之间的过渡层,正余弦过渡使增透性能变强,双曲、指数使增透性能减弱,但影响较小,线性渐变基本没有影响。实验镀制了增透膜并对其进行拟合分析,发现基底与膜层以及膜层之间的过渡层按正余弦变化时与实验结果比较吻合,并给予了解释。

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ZrO2采用X射线衍射(XRD)技术分析了不同充氧条件和沉积温度对ZrO2溥膜组成结构的影响,并对不同工艺下制备的薄膜的表面粗糙度和激光损伤阈值进行了测量。结果发现随着氧压的升高,ZrO2溥膜将由单斜相多晶态逐渐转变为非晶态结构,而随着基片温度的增加,溥膜将由非晶态逐渐转变为单斜相多晶态。同时发现随着氧压升高晶粒尺寸减小,而随着沉积温度增加,晶粒尺寸增大。氧压增加时工艺对表面粗糙度有一定程度的改善,而沉积温度升高,工艺对表面粗糙度的改善不明显。晶粒尺寸大小变化与表面粗糙度变化存在对应关系。激光损伤测量表明

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建立了缺陷吸收升温致薄膜激光损伤模型,该模型从热传导方程出发,考虑了缺陷内部的温度分布以及向薄膜的传导过程,通过引入散射系数简化了Mie散射理论得出的吸收截面.对电子束蒸发沉积的ZrO2:Y2O3单层膜进行了激光破坏实验,薄膜样品的损伤是缺陷引起的,通过辉光放电质谱法对薄膜制备材料的纯度分析发现材料中的主要杂质元素为铂,其含量为0.9%.利用缺陷损伤模型对损伤过程进行了模拟,理论模型和实验结果取得了较好的一致性.

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探讨了不同规律的非均匀性对单层膜的光谱特性的影响,与均匀单层膜对比发现:折射率正变引起透射率的极大值减小,折射率负变引起透射率的极大值变大,当非均匀性很小时,透射率的极小值基本不变.对实验制备的单层膜从实验和理论上进行了对比并给出了较好的拟合,发现在薄膜和基底的界面处存在一过渡层,过渡层可近似为线性,并从理论上给予了分析解释.

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从德鲁德理论出发,对多元共蒸法镀制的非均匀膜的折射率分布与沉积速率的关系进行了探讨;然后利用计算机辅助模拟,对德鲁德分布非均匀光学薄膜,从单周期和多周期、正变和负变、完整周期和存在半周期几个方面对其光学特性进行了系统分析.研究发现:其透射率的极小值和周期数的关系遵从周期数的三次多项式衰减规律,不同规律的德鲁德分布非均匀膜可用来设计不同功能的滤光片.

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研究了高反射膜在多脉冲激光作用下损伤的累积效应.实验中使用1064nm调Q的Nd:YAG激光器,脉宽是12ns,频率为10Hz.实验发现:高反射膜的损伤阈值随辐照脉冲数增加而降低,表现出明显的累积效应.通过对损伤阈值和损伤概率以及辐照次数的统计性研究,并结合单脉冲辐照的结果,说明了存在于薄膜中微小的缺陷参与了多脉冲激光对薄膜的损伤过程,得到了制备IBS高反射膜的损伤闽值和照射次数的关系式,用Nomarski偏光显微镜观察了实验过程中样品的损伤形貌,发现是典型的缺陷损伤.

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多层介质反射镜在非正入射的时候,两个不同的偏振态之间会产生不同的相移.根据空气与膜层、膜层之间的实际情况,建立了界面层和表面吸附层模型,并运用它分析相位延迟产生误差的原因.通过优化设计,入射角为54°,在1285~1345nm之间p,s波获得了270±1°的相移,同时也使反射率在99.5%以上.用离子束溅射技术制备相位延迟膜,用分光光度计测试了光谱特性和用椭偏仪测试了相位特性,在相应波段获得了262.4±1.8°的相移,同时也使反射率在99.6%以上.误差的主要来源是离子源工作特性会产生不均匀的过渡层和最

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对比了背投领域几种主要技术的原理和性能特点,同时介绍了多媒体投影系统所需要的各类光学薄膜的作用,参数和光学性能;并针对该领域国内外最新研究状况进行了调研,给出了现在所面临的关键技术难题并对其发展前景做了预测。

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The single-sided and dual-sided high reflective mirrors were deposited with ion-beam sputtering (IBS). When the incident light entered with 45 degrees, the reflectance of p-polarized light at 1064 nm exceeded 99.5%. Spectrum was gained by spectrometer and weak absorption of coatings was measured by surface thermal lensing (STL) technique. Laser-induced damage threshold (LIDT) was determined and the damage morphology was observed with Lecia-DMRXE microscope simultaneously. The profile of coatings was measured with Mark III-GPI digital interferometer. It was found that the reflectivity of mirror exceeded 99.9% and its absorption was as low as 14 ppm. The reflective bandwidth of the dual-sided sample was about 43 nm wider than that of single-sided sample, and its LIDT was as high as 28 J/cm2, which was 5 J/cm2 higher than that of single-sided sample. Moreover, the profile of dual-sided sample was better than that of substrate without coatings.

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石英晶体振荡监控光学薄膜厚度是直接监控光学薄膜物理厚度的方法,与工作波段无关,设置简单,各种厚度皆可控制.易于实现自动控制,将会越来越广泛地应用在光学薄膜厚度监控中。本文首先介绍了石英晶体监控膜厚仪监控光学薄膜厚度的原理,然后讨论了石英晶体监控仪的发展和晶振片的稳定性。

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Thin-film single layers of Al2O3 and MgF2 were deposited upon super polished fused-silica by electron-beam evaporation. The subsequent optical constants n and k were reported for the spectral range of 180-230 nm. High-reflectance dense multilayer coatings for 193 nm were designed on the basis of the evaluated optical constants and produced. The spectra of the reflectance of HR coatings were compared to the theoretical calculations. HR mirrors of 27 layers with a reflectance of more than 98% were reported. (c) 2004 Elsevier B.V. All rights reserved.

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The laser-induced damage (LID) behavior of narrow-band interference filters was investigated with a Nd:YAG laser at 1064 nm under single-pulse mode and free-running mode. The absorption measurement of such coatings was performed with surface thermal lensing (STL) technique. The damage morphologies under the two different laser modes were also studied in detail. It was found that all the filters exhibited a pass-band-center-dependent absorption and laser-induced damage threshold (LIDT) behavior, but the damage morphologies were diverse. The explanation was given with the analysis of the electric field distribution and the operational behavior of the irradiation laser. (c) 2005 Elsevier B.V. All rights reserved.

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研究了Ta2O5/SiO2硬膜双腔干涉滤光片带内、带边及带外的吸收和激光损伤特性。实验发现,对于作用激光,带通滤光片的驻波场分布、吸收率和损伤阈值在带内、带边和带外的响应特性对作用激光波长均呈现出明显的选择性。根据实验结果,结合滤光片的驻波场分析,给出了带通滤光片的损伤机理。

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Thick metal coatings are currently deposited via two well established routes, Laser or arc based cladding, and thermal spray. A new coating technique known as Laser-assisted Cold Spray (LCS), which aims to expand on the capabilities of the two process routes currently available, is under development at the University of Cambridge in the UK. LCS is a development of the Cold Spray process (CS) in which coatings are built up from powder particles which are entrained within a gas stream and accelerated through a de Laval nozzle, impacting the substrate at supersonic speeds that exceed a material dependent critical velocity.

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通过对主膜系添加匹配层并借助计算机对膜系进行优化,设计出结构规整、性能优良的1064ilm倍频波长分离膜。用电子束蒸发及光电极值监控技术在K9玻璃基底上沉积薄膜,将样品置于空气中在260℃温度下进行3h热退火处理。然后用Lambda 900分光光度计测量了样品的光谱性能;用表面热透镜(STL)技术测量了样品的弱吸收值;用调Q脉冲激光装置测试了样品的抗激光损伤阈值(LIDT)。实验结果发现,样品的实验光谱性能与理论光谱性能有很好的一致性。退火前后其光谱性能几乎没有发生温漂,说明薄膜的温度稳定性好;同时退火使