PVP掺杂-ZrO2溶胶-凝胶工艺制备多层激光高反射膜的研究

以丙醇锆(ZrPr)为锆源,二乙醇胺(DEA)为络合剂,原位引入聚乙烯吡咯烷酮(PVP),在乙醇体系中成功地合成了PVP掺杂-ZrO2溶胶.采用旋涂法在K9玻璃基片上制备了PVP-ZrO2单层杂化薄膜.用不同掺杂量的PVP-ZrO2高折射率膜层与相同的SiO2低折射率膜层交替沉积四分之一波堆高反射膜.借助小角X射线散射研究胶体微结构,用红外光谱、原子力显微镜、紫外/可见/近红外透射光谱、椭圆偏振仪以及1064nm的强激光辐照实验对薄膜的结构、光学和抗激光损伤性能进行表征.研究发现,体系组成的适当配置可以在溶胶稳定的前提下实现ZrPr的充分水解,赋予薄膜良好的结构、光学和抗激光损伤性能.杂化体系中,DEA与ZrPr之间强的配合作用大大降低了ZrO2颗粒表面羟基的活性,使得PVP大分子只是以微弱的氢键与颗粒的表面羟基作用而均匀分散于ZrO2颗粒的周围,对颗粒的形成和生长无显著影响.因而在实验研究范围内,随PVP含量的增大,PVP-ZrO2杂化膜层的折射率和激光损伤阈值均无显著变化.但是,薄膜中均匀分布的PVP柔性链可以有效促进膜层应力松弛,显著削弱不同膜层之间的应力不匹配程度、大大方便多层光学薄膜的制备.当高折射率膜层中PVP的质量分数达到15%-20%时,膜层之间良好的应力匹配使得多层高反射膜的沉积周期数可达到10以上.沉积1O个周期的多层反射膜,在中心波长1064nm处透射率约为1.6%-2.1%,接近全反射特征,其激光损伤阈值为16.4-18.2J/cm2(脉冲宽度为1ns).     

溶胶-凝胶方法制备ZrO2及聚合物掺杂ZrO2单层光学增反射膜

以丙醇锆(Zr(OPr)₄)为原料，乙酸(HAc)为络合剂，聚乙二醇(PEG200)和聚乙烯吡咯烷酮(PVP)为大分子添加剂，在乙醇体系中成功合成了ZrO₂及聚合物掺杂ZrO₂溶胶.用旋涂法在K9玻璃基片上制备单层光学增反射膜.借助小角X射线散射和激光动态光散射技术研究胶体的微结构.采用傅里叶变换红外光谱、差示扫描量热分析、X射线衍射分析、原子力显微镜、紫外/可见/近红外透射光谱以及椭偏仪对薄膜的结构和光学性能进行表征.用输出波长为1064 关键词： 二氧化锆 溶胶-凝胶 增反射膜 激光损伤     

溶胶凝胶ZrO2/SiO2宽带减反膜的制备与性能

采用溶胶凝胶法制备得到以正丙醇锆和正硅酸乙酯为前驱体的ZrO₂和SiO₂溶胶,通过TFCalc光学薄膜软件模拟了ZrO₂/SiO₂三层“宽M型”基频二倍频减反膜,并使用提拉法制备得到了该均匀膜层。三层减反膜在527 nm和1053 nm处的透过率约为99.5%,且透过率大于99%的波长范围均超过150 nm。经热处理后的膜层表面均方根粗糙度为1.34 nm,表面平整性良好;并运用1-on-1激光损伤阈值测试方法测得该减反膜的零几率激光损伤阈值达到36.8 J·cm^-2(1064 nm,10.7 ns)。     

ZrO2／SiO2多层膜中膜厚组合周期数及基底材料对残余应力的影响

ZrO₂／SiO₂多层膜由相同沉积条件下的电子束蒸发方法制备而成， 通过改变多层膜中高(ZrO₂)、低(SiO₂)折射率材料膜厚组合周期数的方法，研究了沉积 在熔石英和BK7玻璃 基底上多层膜中残余应力的变化. 用ZYGO光学干涉仪测量了基底镀膜前后曲率半径的变化， 并确定了薄膜中的残余应力. 结果发现，该多层膜中的残余应力为压应力，随着薄膜中膜厚 组合周期数的增加，压应力值逐渐减小. 而且在相同条件下，石英基底上所沉积多层膜中的 压应力值要小于BK7玻璃基底上所沉积多层膜中的压应力值. 用x射线衍射技术测量分析了膜 厚组合周期数不同的ZrO₂／SiO₂多层膜微结构，发现随着周期数增 加，多层膜的结晶程 度增强. 同时多层膜的微结构应变表现出了与所测应力不一致的变化趋势，这主要是由多层 膜中，膜层界面之间复杂的相互作用引起的. 关键词： 2／SiO₂多层膜')" href="#">ZrO₂／SiO₂多层膜 残余应力 膜厚组合周期数     

溶胶-凝胶ZrO2-TiO2高折射率光学膜层的抗激光损伤性能研究

采用溶胶-凝胶方法制备了ZrO₂-TiO₂(Ti含量为0—100mol%)高折射率光学薄膜. 借助激光动态光散射技术研究溶胶微结构. 采用傅里叶变换红外光谱、原子力显微镜、薄膜光学常数分析仪、漫反射吸收光谱及强激光辐照实验，对膜层的结构、光学性能及抗激光损伤性能进行了系统表征. 结果显示，溶胶-凝胶工艺可以在部分牺牲折射率的情况下，使膜层的抗激光损伤性能得到大幅度提升. 随Ti含量从0mol%增加至100mol%，膜层的平均损伤阈值呈下降趋势，当Ti含量从0mol%增加至60mol%时，平均损伤阈值从57.1J/cm²下降到21.1J/cm²(辐照激光波长为1053nm，脉冲宽度为10ns，“R/1”测试模式)，当Ti含量从60mol%增加至100mol%时，平均损伤阈值变化很小. 综合溶胶微结构、膜层光学性能和损伤实验结果可以推断，强激光诱导多光子吸收是引起膜层损伤的主要原因. 不同配比的复合膜之间光学带隙的显著差异导致相同辐照激光情况下多光子吸收的概率发生变化，从而导致损伤阈值的规律性变化. 关键词： 2-TiO₂薄膜')" href="#">ZrO₂-TiO₂薄膜 溶胶-凝胶 激光诱导损伤 光学带隙     

基于透射光谱确定溶胶凝胶ZrO2薄膜的光学常数

基于溶胶凝胶ZrO₂薄膜的紫外/可见/近红外透射实验光谱,采用Swanepoel方法结合Wemple-DiDomenico色散模型,方便地导出了ZrO₂薄膜在200—1200nm波长范围内的光学常数,包括折射率、色散常数、膜层厚度、吸收系数及能量带隙.研究发现,溶胶凝胶ZrO₂薄膜具有高折射率(1.63—1.93,测试波长为632.8nm)、低吸收和直接能量带隙(4.97—5.63eV) 等光学特性,而且其光学常数对薄膜制备过程中的重要工艺 关键词： 光学常数 Swanepoel方法 2薄膜')" href="#">ZrO₂薄膜 热处理     

溶胶-凝胶方法制备ZrO2及聚合物掺杂ZrO2单层光学增反射膜

以丙醇锆(Zr(OPr)4)为原料,乙酸(HAc)为络合剂,聚乙二醇(PEG200)和聚乙烯吡咯烷酮(PVP)为大分子添加剂,在乙醇体系中成功合成了ZrO2及聚合物掺杂ZrO2溶胶.用旋涂法在K9玻璃基片上制备单层光学增反射膜.借助小角X射线散射和激光动态光散射技术研究胶体的微结构.采用傅里叶变换红外光谱、差示扫描量热分析、X射线衍射分析、原子力显微镜、紫外/可见/近红外透射光谱以及椭偏仪对薄膜的结构和光学性能进行表征.用输出波长为1064 nm的强激光,采用"R/1"模式测试薄膜的抗激光损伤性能.研究发现,改变体系中HAc和H2O的量,可以方便地调节HAc配合反应和H2O分子亲核取代反应发生的概率,从而调控溶胶的稳定性与微结构.在HAc和H2O量配置适当的情况下,原位引入适量的PEG200和PVP可以明显修饰溶胶-凝胶过程,提高溶胶稳定性,促进胶粒之间相互联结成均匀的网络状结构.与溶胶的微结构密切相关,添加PEG200和PVP的薄膜具有更加平整的表面,而膜层均匀的结构及网络状特征赋予薄膜良好的抗激光损伤性能.添加质量分数为10% PEG200和15% PVP的聚合物掺杂ZrO2薄膜,激光损伤阈值可达24.5 J/cm2(脉冲宽度为1 ns);在中心波长λ0处,由反射引起的透射率降低约为2%,显示良好的增反射性能.     

激光诱导多层光学薄膜损伤分析与仿真

提出一种全面分析光学薄膜损伤特性的方法,根据热传导理论与电子增殖理论建立激光辐照下多层介质膜的损伤理论模型。以HfO₂/SiO₂多层高反膜为例,计算红外纳秒脉冲激光作用下膜系内部的温度场、应力场以及自由电子数密度分布,对其热学特性与电子增殖特性进行综合评估后,得到不同输入条件下膜系的损伤阈值。结果表明,薄膜材料的损伤特性会受到驻波场的影响,在1064 nm波长的激光辐照下HfO₂/SiO₂ 多层介质薄膜的热致应力损伤效应先于热熔融效应先于场效应发生,且薄膜中SiO₂层发生热损伤,而薄膜并未发生场损伤,此外薄膜的损伤阈值随着激光脉宽的增大而增大。     

多重分形谱研究溶胶-凝胶SiO2疏水减反膜的激光预处理作用

采用溶胶-凝胶提拉技术制备了SiO₂疏水减反膜.使用Nd：YAG激光（波长为1064nm,脉宽为7.5ns）采用“R on 1”方式对所得膜层进行了激光预处理.在预处理前后采用“1 on 1”方式考察了薄膜的激光损伤阈值的变化,使用原子力显微镜（AFM）观察了薄膜的表面形貌的变化,并使用多重分形谱（MFS）方法分析了薄膜分形结构的变化.结果表明经过激光预处理后薄膜的抗激光损伤阈值有了明显提高,均方根表面粗糙度（R_q）稍有减小,膜面变平整,多重分形谱宽度收缩,分形区间的分布均匀性改善.这说明经过激光预处理后薄膜表面微结构趋向规整,使之能够承受更强的激光的辐照.同时也说明借助多重分形谱可以获得更多薄膜表面结构变化的信息,多重分形谱是探索强激光对光学薄膜辐照作用机理的一个十分有用的方法. 关键词： 2疏水减反膜')" href="#">SiO₂疏水减反膜 激光预处理 多重分形谱 激光损伤阈值     

Au/SiO2纳米多层薄膜的制备及其性质表征

利用多靶磁控溅射技术制备了Au/SiO₂纳米颗粒分散氧化物多层复合薄膜.研究了在保持Au单层颗粒膜沉积时间一定时薄膜厚度一定、变化SiO₂的沉积时间及SiO₂的沉积时间一定而改变薄膜厚度时，多层薄膜在薄膜厚度方向的微观结构对吸收光谱的影响.研究结果表明：具有纳米层状结构的Au/SiO₂多层薄膜在560 nm波长附近有明显的表面等离子共振吸收峰，吸收峰的强度随Au颗粒的浓度增加而增强，在Au颗粒浓度相同的情况下，复合薄膜 关键词： 2纳米复合薄膜')" href="#">Au/SiO₂纳米复合薄膜 多靶磁控溅射 吸收光谱 有效介质理论     

Influences of CO2 laser annealing on mechanical and laser-induced damage properties of ZrO2 thin films

Zirconium dioxide (ZrO₂) thin films were deposited on BK7 glass substrates by the electron beam evaporation method. A continuous wave CO₂ laser was used to anneal the ZrO₂ thin films to investigate whether beneficial changes could be produced. After annealing at different laser scanning speeds by CO₂ laser, weak absorption of the coatings was measured by the surface thermal lensing (STL) technique, and then laser-induced damage threshold (LIDT) was also determined. It was found that the weak absorption decreased first, while the laser scanning speed is below some value, then increased. The LIDT of the ZrO₂ coatings decreased greatly when the laser scanning speeds were below some value. A Nomarski microscope was employed to map the damage morphology, and it was found that the damage behavior was defect-initiated both for annealed and as-deposited samples. The influences of post-deposition CO₂ laser annealing on the structural and mechanical properties of the films have also been investigated by X-ray diffraction and ZYGO interferometer. It was found that the microstructure of the ZrO₂ films did not change. The residual stress in ZrO₂ films showed a tendency from tensile to compressive after CO₂ laser annealing, and the variation quantity of the residual stress increased with decreasing laser scanning speed. The residual stress may be mitigated to some extent at proper treatment parameters.     

Preparation of sol-gel ZrO2-SiO2 highly reflective multilayer films and laser-induced damage threshold characteristic

Sol-gel (ZrO₂/SiO₂)¹² ZrO₂ films were prepared by spin coating method. The reflectivity spectrum of the films was measured with a Lambda 900 spectrometer. In order to investigate laser-induced damage threshold (LIDT) characteristic of highly reflective films, one-layer ZrO₂ and SiO₂ films, two-layer ZrO₂/SiO₂ and SiO₂/ZrO₂ films were also prepared by spin coating method. LIDT of each film was measured. Damage morphology after laser irradiation was characterized by optical microscopy (Nikon E600K). The experimental results showed that the reflectivity of (ZrO₂/SiO₂)¹² ZrO₂ film at 1064 nm and 355 nm wavelength is 99.7%. The LIDT results decreases as the number of layer of films increases. All the films have similar damage morphology. The experimental results are explained by the different temperature profiles of the films.     

Influence of SiO2 additional layers on the laser induced damage threshold of Ta2O5 films

A series of Ta₂O₅ films with different SiO₂ additional layers including overcoat, undercoat and interlayer was prepared by electron beam evaporation under the same deposition process. Absorption of samples was measured using the surface thermal lensing (STL) technique. The electric field distributions of the samples were theoretical predicted using thin film design software (TFCalc). The laser induced damage threshold (LIDT) was assessed using an Nd:YAG laser operating at 1064 nm with a pulse length of 12 ns. It was found that SiO₂ additional layers resulted in a slight increase of the absorption, whereas they exerted little influence on the microdefects. The electric field distribution among the samples was unchanged by adding an SiO₂ overcoat and undercoat, yet was changed by adding an interlayer. SiO₂ undercoat. The interlayer improved the LIDT greatly, whereas the SiO₂ overcoat had little effect on the LIDT.     

电子束蒸发氧化锆薄膜的粗糙度和光散射特性

利用电子束蒸发工艺，以Ag层为衬底，沉积了中心波长为632.8nm的氧化锆(ZrO₂)薄膜，膜层厚度在80—480nm范围内变化.研究了不同厚度样品的粗糙度变化规律和表面散射特性.结果发现，随着膜层厚度的逐渐增加，其表面均方根(RMS)粗糙度和总积分散射(TIS)均呈现出先减小后增大的趋势.利用非相关表面粗糙度的散射模型对样品的TIS特性进行了理论计算，所得结果与测量结果相一致. 关键词： 氧化锆 表面粗糙度 标量散射 电子束蒸发     

Influence of porosity on laser damage threshold of sol–gel ZrO2 and SiO2 monolayer films

Monolayer ZrO₂ sol–gel and physical vapor deposition (PVD) films were prepared by spin method and electron beam evaporation method, respectively. Monolayer sol–gel SiO₂ films were prepared with the dip-coating method from acid and base catalyzed SiO₂ sols, respectively. Some of the SiO₂ base films were subsequently treated in saturated ammonia gas for 20 h. The laser induced damage threshold (LIDT) of each film was measured. Properties of the films were analyzed by using Stanford photo-thermal solutions (SPTSs), ellipsometer, atomic force microscopy (AFM) and optical microscopy. The experimental results showed that porous ratio is an essential factor to decide the LIDT for sol–gel films, which benefits the pressure exerted on the film or substrate by the moving particle to dissipate. The films with lower thermal absorption and higher porous ratio have higher LIDT.     

XPS investigation of diffusion of two-layer ZrO2/SiO2 and SiO2/ZrO2 sol–gel films

Two-layer ZrO₂/SiO₂ and SiO₂/ZrO₂ films were deposited on K9 glass substrates by sol–gel dip coating method. X-ray photoelectron spectroscopy (XPS) technique was used to investigate the diffusion of ZrO₂/SiO₂ and SiO₂/ZrO₂ films. To explain the difference of diffusion between ZrO₂/SiO₂ and SiO₂/ZrO₂ films, porous ratio and surface morphology of monolayer SiO₂ and ZrO₂ films were analyzed by using ellipsometry and atomic force microscopy (AFM). We found that for the ZrO₂/SiO₂ films there was a diffusion layer with a certain thickness and the atomic concentrations of Si and Zr changed rapidly; for the SiO₂/ZrO₂ films, the atomic concentrations of Si and Zr changed relatively slowly, and the ZrO₂ layer had diffused through the entire SiO₂ layer. The difference of diffusion between ZrO₂/SiO₂ and SiO₂/ZrO₂ films was influenced by the microstructure of SiO₂ and ZrO₂.     

X-ray photoelectron spectroscopy of nano-multilayered Zr-O/Al-O coatings deposited by cathodic vacuum arc plasma

Nano-multilayered Zr-O/Al-O coatings with alternating Zr-O and Al-O layers having a bi-layer period of 6-7 nm and total coating thickness of 1.0-1.2 μm were deposited using a cathodic vacuum arc plasma process on rotating Si substrates. Plasmas generated from two cathodes, Zr and Al, were deposited simultaneously in a mixture of Ar and O₂ background gases. The Zr-O/Al-O coatings, as well as bulk ZrO₂ and Al₂O₃ reference samples, were studied using X-ray photoelectron spectroscopy (XPS). The XPS spectra were analyzed on the surface and after sputtering with a 4 kV Ar⁺ ion gun. High resolution angle resolved spectra were obtained at three take-off angles: 15°, 45° and 75° relative to the sample surface.It was shown that preferential sputtering of oxygen took place during XPS of bulk reference ZrO₂ samples, producing ZrO and free Zr along with ZrO₂ in the XPS spectra. In contrast, no preferential sputtering was observed with Al₂O₃ reference samples. The Zr-O/Al-O coatings contained a large amount of free metals along with their oxides. Free Zr and Al were observed in the coating spectra both before and after sputtering, and thus cannot be due solely to preferential sputtering.Transmission electron microscopy revealed that the Zr-O/Al-O coatings had a nano-multilayered structure with well distinguished alternating layers. However, both of the alternating layers of the coating contained of a mixture of aluminum and zirconium oxides and free Al and Zr metals. The concentration of Zr and Al changed periodically with distance normal to the coating surface: the Zr maximum coincided with the Al minimum and vice versa. However the concentration of Zr in both alternating layers was significantly larger than that of Al. Despite the large free metal concentration, the Knoop hardness, 21.5 GPa, was relatively high, which might be attributed to super-lattice formation or formation of a metal-oxide nanocomposite within the layers.