LBO晶体上1 064，532 nm倍频增透膜的镀制及性能分析

 用电子束蒸发沉积方法在X切LBO（X-LBO）晶体上镀制了两种不同膜系结构的1 064和532 nm倍频增透膜，其中一种膜系结构为基底/ZrO₂/Y₂O₃/Al₂O₃/SiO₂/空气，另一种为基底/0.5Al₂O₃/ZrO₂/Y₂O₃/Al₂O₃/SiO₂/空气，两种膜系结构的主要差别在于有无氧化铝过渡层。测量了薄膜的反射率光谱曲线，发现两种增透膜在1 064和532 nm处的反射率均小于0.5％，实际镀制结果与理论设计曲线的差异主要是由材料折射率的变化引起的。且对样品在空气环境中进行了温度为473 K的退火处理，结果发现两种膜系结构均表现了较优异的光学性能，氧化铝过渡层的加入使薄膜具有强的热应力性能。     

4H-SiC基底Al_2O_3/SiO_2双层减反射膜的设计和制备

在4H-SiC基底上设计并制备了Al2O3SiO2紫外双层减反射膜,通过扫描电镜(SEM)和实测反射率谱来验证理论设计的正确性.利用编程计算得到Al2O2和SiO2的最优物理膜厚分别为42.0 nm和96.1 nm以及参考波长λ=280 nm处最小反射率为0.09%.由误差分析可知,实际镀膜时保持双层膜厚度之和与理论值一致有利于降低膜系反射率.实验中应当准确控制SiO2折射率并使Al2O3折射率接近1.715.用电子束蒸发法在4H-SiC基底上淀积Al2O3SiO2双层膜,厚度分别为42 nm和96 nm.SEM截面图表明淀积的薄膜和基底间具有较强的附着力.实测反射率极小值为0.33%,对应λ=276 nm,与理论结果吻合较好.与传统SiO2单层膜相比,Al2O3SiO2双层膜具有反射率小,波长选择性好等优点,从而论证了其在4H-SiC基紫外光电器件减反射膜上具有较好的应用前景.     

Effect of λ/2 SiO_2 overcoat on the laser damage of HfO_2/SiO_2 high-reflector coatings

The effect of λ/2 SiO2 overcoat on the laser damage characteristics of HfO2/SiO2 high-reflector (HR) coatings is investigated with 1-on-l and N-on-1 laser damage test methods. The laser damage surface of 1-on-l is analyzed by a step analyzer. The surface morphologies show that laser damage makes the coating damaged area protrudent and rough for HR coating without λ/2 silica overcoat, but concave and smooth for HR coating with A/2 silica overcoat. The result of 10-on-l multi-pulse irradiation on the same point of the coating shows that there is an energy density stage on the damage curve. If the laser energy density is within the range of the stage, HfO2/SiO2 HR coatings with λ/2 silica overcoat will not be damaged more than 2 times for multi-shots, and the surface damages are very slight so that there is no impact on the coating performance. Another interesting result is that the energy density stage extends from the damage threshold to the point of about 3 times of threshold, which is similar to the     

缓冲层对LBO晶体上1 064 nm，532 nm增透膜附着力的影响

 采用电子束蒸发方法在LBO晶体上制备了无缓冲层和具有不同缓冲层的1 064 nm,532 nm二倍频增透膜。利用分光光度计、纳米力学综合测试系统以及调Q脉冲激光装置对样品的光学性能、附着力以及抗激光损伤性能进行了测试分析。结果表明：所有样品在1 064 nm和532 nm波长的剩余反射率都分别小于0.1％和0.2％;与无缓冲层样品相比,预镀Al₂O₃缓冲层样品的附着力提高了43.1％,具有SiO₂缓冲层样品的附着力显著提高,而MgF₂缓冲层的插入却导致薄膜附着力降低。应用全塑性压痕理论和剪切理论对薄膜的附着力增强机制进行了分析。薄膜的抗激光损伤性能分析表明,SiO₂缓冲层也有助于改进薄膜的激光损伤阈值。     

太阳能玻璃表面高强度双层减反膜制备研究

用膜系设计软件设计了λ/4-λ/2的W型的双层减反射薄膜,优化了薄膜的光学常量,并使用溶胶-凝胶技术在玻璃基底上成功镀制了该双层折射率梯度的减反射薄膜.用椭圆偏振光谱仪、紫外-可见-近红外分光光度计、原子力显微镜等分析表征了薄膜的性能.结果表明,镀制了该双层薄膜的玻璃在400 nm～800 nm波段平均透过率增加了近6%,同时薄膜显示出了极佳的机械强度.     

Research on the UV Dielectric Coatings with High Damage Threshold

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Adhesion properties of a silicon-containing calcium phosphate coating deposited by RF magnetron sputtering on a heated substrate

Silicon-containing hydroxyapatite coatings 400–700 nm in thickness are prepared by means of radio-frequency (RF) magnetron sputtering on a heated (to 200°C) titanium substrate chemically etched and treated with a pulsed electron beam. The morphology and phase composition of the coating are studied. The morphology and roughness of the composite “calcium-phosphate coating-titanium substrate” differ depending on the treatment procedure of the substrate before deposition. The scratch test method is used to assess the adhesion strength of the coatings formed at different values of bias potential applied to the substrate. It is observed that the adhesion strength of the coating changes with decreasing crystallite size.     

聚乙烯醇/二氧化硅复合增透膜的制备和可清除性

 用溶胶-凝胶法制备了易清洗的聚乙烯醇/二氧化硅(PVA/SiO₂)复合增透膜。先在K9玻璃基片上镀制PVA薄膜,然后在PVA薄膜上镀上二氧化硅增透膜。用紫外可见光分光光度计、椭偏仪、光学显微镜、扫描探针显微镜和静滴接触角测量仪分别分析了膜层和基片的透射率、膜层厚度和折射率、表面形貌、水接触角等性质,用去离子水作溶剂对复合膜层进行清洗。结果表明：聚乙烯醇/二氧化硅复合增透膜峰值透射率达到99.8％,峰值透射率位置可以随SiO₂厚度而调节。复合膜层能够被热水清除,清除后基片完好,其透射率、表面形貌和水接触角与镀膜前一致。     

A novel trilayer antireflection coating using dip-coating technique

We report a new structure for broadband antireflection coating by dip-coating technique, which has minimal cost and is compatible with large-scale manufacturing. The coatings are prepared by depositing SiO 2 sol-gel film on a glass substrate, subsequently depositing SiO 2 single-layer particle coating through electrostatic attraction, and depositing a final very thin SiO 2 sol-gel film to improve the mechanical strength of the whole coating structure. The refractive index of the structure changes gradually from the top to the substrate. The transmittance of a glass substrate has been experimentally found to be improved in the spectral range of 400 1 400 nm and in the incidence angle range from 0 to at least 45 . The mechanical strength is immensely improved because of the additional thin SiO 2 sol-gel layer. The surface texture can be applied to the substrates of different materials and shapes as an add-on coating.     

Enhanced laser induced damage threshold of dielectric antireflection coatings by the introduction of one interfacial layer

A new method for increasing laser induced damage threshold (LIDT) of dielectric antireflection (AR) coating is proposed. Compared with AR film stack of H2.5L (H:HfO2, L:SiO2) on BK7 substrate, SiO2 interfacial layer with four quarter wavelength optical thickness (QWOT) is deposited on the substrate before the preparation of H2.5L film. It is found that the introduction of SiO2 interfacial layer with a certain thickness is effective and flexible to increase the LIDT of dielectric AR coatings. The measured LIDT is enhanced by about 50%, while remaining the low reflectivity with less than 0.09% at the center wavelength of 1064 nm. Detailed mechanisms of the LIDT enhancement are discussed.     

Preparation and in vitro characterization of aerosol-deposited hydroxyapatite coatings with different surface roughnesses

Hydroxyapatite (HA) coatings with different surface roughnesses were deposited on a Ti substrate via aerosol deposition (AD). The effect of the surface roughness on the cellular response to the coating was investigated. The surface roughness was controlled by manipulating the particle size distribution of the raw powder used for deposition and by varying the coating thickness. The coatings obtained from the 1100 °C-heated powder exhibited relatively smooth surfaces, whereas those fabricated using the 1050 °C-heated powder had network-structured rough surfaces with large surface areas and were superior in terms of their adhesion strengths and in vitro cell responses. The surface roughness (R_a) values of the coatings fabricated using the 1050 °C-heated powder increased from approximately 0.65 to 1.03 μm as the coating thickness increased to 10 μm. The coatings with a rough surface had good adhesion to the Ti substrate, exhibiting high adhesion strengths ranging from 37.6 to 29.5 MPa, depending on the coating thickness. The optimum biological performance was observed for the 5 μm-thick HA coating with an intermediate surface roughness value of 0.82 μm.     

透射光谱法测试双面薄膜的光学参数

由于普通的化学气相沉积法制作高掺Sn的二氧化硅薄膜比较容易产生结晶,而溶胶-凝胶法制备薄膜化学组成比较容易控制,可以制作出掺Sn浓度较大的材料。文章采用了溶胶-凝胶的方法制备出了66 mol%和75 mol%两种不同浓度的掺Sn的SiO₂薄膜,用浸渍法多次提拉薄膜以增加薄膜的厚度,之后用紫外-可见分光光度计测量了薄膜的透射光谱。之前基于透射光谱的方法计算玻璃基底上薄膜的光学参数都是针对单面薄膜,该文针对浸渍法产生的双面薄膜,建立了相对应的薄膜模型,并分别用包络线法计算出了两种不同薄膜样品的光学参数。计算结果表明两种不同薄膜样品的折射率随着波长的增加而增加,薄膜的厚度都为900 nm左右。     

Plasma-assisted deposition of a three-layer structure by vacuum andgas arcs

The durability and adhesion of thin coatings often depends on the structure and properties of the layer intermediate between the coating and the substrate, especially in the case where the layer and the substrate are highly different in microhardness. With a vacuum arc and a hot-cathode arc, a process has been arranged which involves cleaning of the surface, nitration of the article, and deposition of a coating. As a result, a three-layer composition has been produced which consists of a TiN layer of thickness up to 5 μm and microhardness 20 GPa, an intermediate Fe₄N layer of thickness up to 8 μm and microhardness 7.5 GPa, and a nitrated layer of thickness up to 100 μm with a gradually varying microhardness. With the TiN layer showing high adhesion, the coating has a durability three of four times greater than that of a coating produced with the use of a conventional technology     

Characteristic and biocompatibility of the TiO2-based coatings containing amorphous calcium phosphate before and after heat treatment

TiO₂-based coating containing amorphous calcium phosphate (CaP) was prepared on titanium alloy by microarc oxidation (MAO). The increase in the EDTA-2Na concentration was unfavorable for the crystallization of TiO₂. After heat treatment, the amorphous CaP was crystallized. The thickness of the MAO coatings did not change when heat-treated at 400, 600 and 700 °C; while it increased slightly after heat treatment at 800 °C due to the crystallization of amorphous CaP and growth of TiO₂. No apparent discontinuity between the coatings and substrates was observed at various heat-treatment temperatures, indicating the MAO coatings with good interfacial bonding to the substrate. The heat treatment did not alter the chemical composition of the MAO coating and the chemical states of Ti, Ca and P elements. However, it increased the roughness (Ra) of the MAO coating and improved the wetting ability of the MAO coating. In this work, preliminary investigation of the MG63 cell proliferation on the surface of the MAO and heat-treated MAO coatings was conducted. The MAO coating surface with about Ra = 220 nm may be suitable for the MG63 cell adhesion and proliferation. The increased roughness of the heat-treated MAO coatings may result in a decrease in the ability for cell adhesion and proliferation.     

氧化物薄膜抗1064nm脉冲激光损伤的特性研究

对向种氧化物介质膜料的单层膜、增透膜及高反膜的激光损伤特性进行了实验研究,分别测试了单脉冲和多脉冲１０６４ｎｍ激光的损伤阈值,分析和讨论了实验的物理现象及其结果。研究表明ＳｉＯ２、Ｇｄ２Ｏ３、Ｅｒ２Ｏ３、Ｙ２Ｏ３具有激光损伤阈值高、损伤程度轻的特点,特别对１０Ｈｚ激光而言,更是明显;增透膜及高反膜加λ／２层ＳｉＯ２对其激光损伤程度和损伤几率。     

X-ray photoelectron spectroscopy study of the growth kinetics of biomimetically grown hydroxyapatite thin-film coatings

Hydroxyapatite (HA) thin-film coatings grown biomimetically using simulated body fluid (SBF) are desirable for a range of applications such as improved fixation of fine- and complex-shaped orthopedic and dental implants, tissue engineering scaffolds and localized and sustained drug delivery. There is a dearth of knowledge on two key aspects of SBF-grown HA coatings: (i) the growth kinetics over short deposition periods, hours rather than weeks; and (ii) possible difference between the coatings deposited with and without periodic SBF replenishment. A study centred on these aspects is reported. X-ray photoelectron spectroscopy (XPS) has been used to study the growth kinetics of SBF-grown HA coatings for deposition periods ranging from 0.5 h to 21 days. The coatings were deposited with and without periodic replenishment of SBF. The XPS studies revealed that: (i) a continuous, stable HA coating fully covered the titanium substrate after a growth period of 13 h without SBF replenishment; (ii) thicker HA coatings about 1 μm in thickness resulted after a growth period of 21 days, both with and without SBF replenishment; and (iii) the Ca/P ratio at the surface of the HA coating was significantly lower than that in its bulk. No significant difference between HA grown with and without periodic replenishment of SBF was found. The coatings were determined to be carbonated, a characteristic desirable for improved implant fixation. The atomic force and scanning electron microscopies results suggested that heterogeneous nucleation and growth are the primary deposition mode for these coatings. Primary osteoblast cell studies demonstrated the biocompatibility of these coatings, i.e., osteoblast colony coverage of approximately 80%, similar to the control substrate (tissue culture polystyrene).     

一种评估液晶显示器件中使用的SiO2膜层性能的新方法

玻璃基片上的ＳｉＯ２膜已在液晶显示器件制造业中得到了广泛应用，ＳｉＯ２膜性能在很大程度上决定了液晶显示器件的化学稳定性及使用寿命，ＳｉＯ２膜致密性及膜厚可由Ｐ－蚀刻法测量出。本文提出了一种评估液晶显示器件中使用ＳｉＯ２膜层性能的简便而又快捷的方法。     

Interlayer effect on the characterization of the La-Cr-O coatings with post-sputtering annealing treatment

In this study, the deposition of La-Cr-O coatings on AISI 316 stainless steel was conducted by using a DC magnetron sputtering process. Three types of La-Cr-O coatings were designed, one type without interlayer, and another two types with an interlayer of Cr and CrN film, separately. This study aims to explore the interlayer effect on the properties of La-Cr-O coatings after post-annealing treatment. The coatings were characterized using the X-ray diffractionmeter (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and thermal gravimetric analysis (TGA)/differential scanning calorimetry (DSC).The results showed that the three as-deposited La-Cr-O coatings had an amorphous structure. After annealing at 800 °C for 1 h in the air, the structure was transformed to the LaCrO₃ perovskite phase. Compared with the coatings without an interlayer, the double-layered coatings did not show the Cr₂O₃ phase in the structure. It implies that the use of the interlayer in the coatings could efficiently prohibit the diffusion of Cr to form oxide on the out-layer. Based on the TGA/DSC analysis and the electrical resistance measurement, it is understood that the annealed La-Cr-O coating with the CrN interlayer turns in the best performance in both chemical stability at high temperature and electrical resistance.     

SiO_2溶胶的簇团特性及其对增透膜光学性能的影响

在碱性条件下制备的ＳｉＯ２溶胶,经旋转法镀膜,得到具有增透效果的膜层。结果表明随着与陈化温度和陈化时间密切相关的溶胶族团的粒度分布及交联行为直接影响膜层的增透效果,膜层增透效果与溶胶族团的特性间存在一定的内在规律。     

SiO2半波覆盖层对HfO2／SiO2高反射膜激光损伤的影响

研究了SiO2半波覆盖层对HfO2／SiO2高反射膜1064nm激光损伤的影响,分析薄膜的激光损伤特性及图貌得出-对于单脉冲(1-ON-1)激光损伤,SiO2半波覆盖层能提高HfO2／SiO2高反射膜的激光损伤厨值,可显著降低激光损伤程度,减小灾难性损伤发生的概率,可大幅度提高FIfO2／SiO2高反射膜的抗激光损伤能力。