215 resultados para Coatings Grout


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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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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

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利用电子束蒸发方法在Yb:YAG晶体和熔融石英衬底上沉积单层ZrO2薄膜,分别在673 K和1 073 K的温度下经过12 h退火以后,通过X射线衍射(XRD)分析了薄膜晶相,计算了薄膜的晶粒尺寸;利用表面热透镜技术获得了薄膜的吸收;测量了退火后薄膜的激光损伤阈值.实验结果表明:两种衬底上的薄膜结构受到退火温度和衬底表面结构的影响,高温退火有利于单斜相的形成,含单斜相的ZrO2薄膜具有较高的激光损伤阈值,而由于衬底的吸收,Yb:YAG晶体上薄膜的损伤阈值远小于石英衬底上薄膜的损伤阈值.

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对双源线性共蒸法制备的非均匀薄膜折射率分布与光学特性的关系作了探讨,并与均匀介质膜的光学特性作了对比;从折射率正变和负变两个方面.讨论了混合介质膜折射率不同变化规律对光学性能带来的影响;讨论了厚度误差和折射率极值误差对非均匀膜光学性能的影响。结果发现:折射率变化规律误差主要对非均匀膜的应用波段范围产生影响,而膜层厚度误差和折射率极值误差超过一定值时,将对薄膜光学特性产生重要影响。

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本文研究了在镀膜过程中真空室内水蒸气的含量对HfO2薄膜物理性能的影响。用电子束蒸发和光电极值监控的方法在BK7基底上制备HfO2薄膜。利用残余气体分析仪在线监测了真空室内的残余气氛组成。分别用Lambda 900光谱仪、X射线衍射方法、表面热透镜技术和1064nm的激光器测试了薄膜的光学性能、微结构、吸收和激光损伤阈值。实验发现,附加冷阱装置有助于我们有效控制镀膜过程中的水汽含量,且在水蒸气含量较少的真空室内镀制的薄膜具有较高的折射率,较小的晶粒尺寸,较低的弱吸收值和较高的损伤阈值。

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本文主要研究了真空中有机污染物对薄膜阈值的影响。采用电子枪蒸镀的方式制备了由TiO2/SiO2两种材料组合而成的1064nm高反膜,分别在大气和真空中对其损伤阈值进行了测量。发现在真空中污染物易黏附于光学元件表面,导致损伤;真空中的氧分子会加速损伤过程,根据破斑形貌的分析认为是由于在激光作用下氧分子与有机污染物发生反应造成的;真空中的有机污染物被去除后,真空和大气中的损伤阈值差别不大,破斑形貌相似。结果表明有机污染物是真空中损伤阈值降低的主要原因。

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Glancing angle deposition is a novel method to prepare graded index coatings. By using this method and physical vapour deposition, ZrO2 is used to engineer graded index filter on BK7 glass substrate. Controlling the deposition rate and the periodic oscillation of oblique angle of deposited material, a 10-period graded index ZrO2 filter with high reflection near 532 nm and high transmittance at wavelength 1064 nm is fabricated. The causes of difference between the theoretical and experimental results are discussed in detail. The material properties and electron gun nonlinearity are possibly the main origins of the difference, which result in the variations in both thickness control and deposition rate of the Elm material.