磁控反应溅射法制备渐变折射率薄膜的模型分析

阐述了磁控反应溅射法制备渐变折射率薄膜的机理；探讨了磁控反应溅射法制备渐变折射率薄膜的理论模型，给出了渐变折射率薄膜的折射率与反应气体分压的关系，在一定的沉积参数下，由要得到的膜层折射率随膜层几何厚度的变化规律可推导出反应气体分压比随时间的变化规律；最后以制备折射率线性变化的薄膜为例说明了如何推导得到反应气体分压比随时间的变化规律．

共蒸法制备非均匀膜的速率控制分析

渐变折射率薄膜，又称为非均匀膜。利用德鲁德理论分析了混合介质膜的介电常量与各个膜料的介电常量之间的关系，介绍了共蒸法制备非均匀膜的制备机理。对混合膜的沉积速率为两种膜料的沉积速率之和的情况，分别从两种膜料的单分子体积是否相等和总的沉积速率是否为常数两个方面，探讨了双源共蒸法制备的非均匀膜的折射率分布规律与膜料的沉积速率之间的关系，并给出了几种常见的折射率分布如线性变化、正弦变化、指数变化和双曲变化规律的膜料沉积速率表达式。最后以混合介质膜的总沉积速率为常数、折射率按照线性变化为例进行了说明。

Design and properties analysis of multi-layer dielectric used in pulse compressor gratings

Used in chirped-pulse amplification system and based on multi-layer thin film stack, pulse compressor gratings (PCG) are etched by ion-beam and holographic techniques. Diffraction efficiency and laser-induced damage threshold rely on the structural parameters of gratings. On the other hand, they depend greatly on the design of multi-layer. A theoretic design is given for dielectric multi-layer, which is exposed at 413.1 nm and used at 1053 nm. The influences of coating design on optical characters are described in detail. The analysis shows that a coating stack of H3L (H2L) (boolean AND) 9H0.5L2.01H meets the specifications of PCG well. And there is good agreement of transmission between experimental and the theoretic design. (c) 2005 Elsevier GmbH. All rights reserved.

Laser-induced damage morphology of high-reflective optical coatings

Two different kinds of 1064 nm high-reflective (HR) coatings, with and without SiO2 protective layer, were prepared by electron beam evaporation. Three-dimensional damage morphology, caused by a Nd:YAG pulsed laser, was investigated for these HR coatings. Development of laser-induced damage on HR coatings was revealed by both temperature field calculation and discrete meso-element simulation. Theoretical results met experimental very well. (C) 2004 Elsevier B.V. All rights reserved.

LBO晶体上1064nm，532nm二倍频增透膜的设计及误差分析

采用矢量合成法设计了LiB3O5（LBO）晶体上1064nm，532nm二倍频增透膜，在1064nm处的反射率为0．0014％，532nm处的反射率为0．0004％。根据误差分析，薄膜制备时沉积速率精度控制在＋6．5％时，1064nm处的反射率增加至0．22％，532nm处增加至0．87％。材料折射率的变化控制在＋3％时，1064nm处的反射率达0．24％，532nm处达0．22％。沉积速率和折射率控制的负变化不增大特定波长处的剩余反射率。与膜层折射率相比，薄膜物理厚度对剩余反射率的影响小。低折射率膜层的

利用分光光度计测量光学晶体的折射率

晶体折射率的准确测定是晶体上薄膜器件设计的基础。介绍了利用分光光度计测量晶体折射率的方法，通过背面影响系数法、背面镀增透膜和将两者结合起来的方法消除晶体反射率测量时背面反射带来的影响，给出了具体的步骤并对测量误差进行了分析。由于晶体的光学各向异性，采用起偏器扫描的方法测量晶体光学性质随方向的变化。通过对LiB3P5晶体的折射率的测量，证实了该方法的可行性并可用于其他光学晶体折射率的测量。

Laser conditioning of ZrO2 : Y2O3/SiO2 mirror coatings prepared by E-beam evaporation

Laser conditioning effects of the dielectric mirror coatings with different designs were investigated. Simple quarter-wave ZrO2:Y2O3/SiO2 mirrors and half-wave SiO2 over-coated ZrO2:Y2O3/SiO2 mirror coatings were fabricated by E-beam evaporation (EBE). The absorbance of the samples before and after laser conditioning was measured by surface thermal lensing (STL) technology and the defects density was detected under Nomarski microscope. The enhancement of the laser damage resistance was found after laser conditioning. The dependence of the laser conditioning on the coating design was also observed and the over-coated sample obtained greatest enhancement, whereas the absorbance of the samples did not change obviously. During the sub-threshold fluence raster scanning, the minor damage about defects size was found and the assumption of pre-damage mechanism, based on the functional damage concept, was put forward. The improvement of the laser induced damage threshold (LIDT) was attributed to the benign damage of the defects and the dependence on the coating design owed to the damage growth behavior of different coating designs. (C) 2004 Elsevier B.V. All rights reserved.

Stress, absorptance and laser-induced damage threshold properties of 355-nm HR coatings

A number of 355-nm Al2O3/MgF2 high-reflectance (HR) coatings were prepared by electron-beam evaporation. The influences of the number of coating layers and deposition temperature on the 355-nm Al2O3/MgF2 HR coatings were investigated. The stress was measured by viewing the substrate deformation before and after coating deposition using an optical interferometer. The laser-induced damage threshold (LIDT) of the samples was measured by a 355-nm Nd:YAG laser with a pulse width of 8 ns. Transmittance and reflectance of the samples were measured by a Lambda 900 spectrometer. It was found that absorptance was the main reason to result in a low LIDT of 355-nm Al2O3/MgF2 HR coatings. The stress in Al2O3/MgF2 HR coatings played an unimportant role in the LIDT, although MgF2 is known to have high tensile stress.

Study of Al2O3/MgF2 HR coatings at 355 nm

With the present work we tried to study the effective methods to improve the laser-induced damage threshold (LIDT) and reflectance of HR coatings at 355 nm. The work presented in this paper wits part of an ongoing study about vacuum annealing. It was dedicated to study the effects Of Vacuum annealing with different temperature gradients on the structure, optical properties and laser-induced damage threshold (LIDT) of 355nm Al2O3/MgF2HR coatings. A number of samples were prepared by electron beam evaporation using the same deposition process with an optimal deposition temperature of 280 degrees C. After deposition, samples were annealed in the coating chamber for 3 h with different temperature gradients. Morphologies of the samples were observed by Leica-DMRXE. Microscope, Structure of the samples had been characterized by X-ray diffraction (XRD). Transmittance and reflectance of the samples were measured by Lambda 900 Spectrometer, The LIDT of the samples was measured by a 355 nm Nd:YAG laser with a pulse width of 8 ns. It was found that the temperature gradient of vacuum annealing had significant effects on the morphology, structure, absorption, and LIDT of the samples, (c) 2005 Elsevier Ltd. All rights reserved.

负离子元素杂质破坏模型

探讨了HfO2薄膜中负离子元素杂质破坏模型，并得出薄膜中的杂质主要来源于镀膜材料。用电子束蒸发方法沉积两种不同Cl元素古量的HfO2薄膜，测定薄膜弱吸收和损伤阈值来验证负离子元素破坏模型。结果表明，随着Cl元素含量的增加薄膜的弱吸收增加损伤阈值减小。这主要是因为负离子元素在蒸发过程中形成挥发性的气源中心而产生缺陷，缺陷在激光辐照过程中又形成吸收中心．因此负离子元素的存在将加速薄膜的破坏。

斜角入射沉积法制备渐变折射率薄膜的折射率分析

斜角入射沉积法是一种制备薄膜的新颖方法，它可以用来制备渐变折射率薄膜．本文首先探讨了膜料的沉积入射角为α，薄膜柱状生长倾斜角为β时的薄膜的填充系数；之后利用drude理论，分析研究了斜角入射沉积法制备渐变折射率薄膜的折射率与薄膜的入射角和生长方向的关系．

钛宝石激光器中用优化Gires-Tournois镜产生15fs脉冲

根据飞秒脉冲锁模钛宝石激光器脉冲压缩的要求，介绍了负色散镜补偿色散的基本原理及其特点。详细阐述了优化Gires-Tournois(OG-T)镜的设计过程，并通过计算机优化得到理想设计膜系。采用离子束溅射的方法镀制了优化Gires—Tournois镜。测量了优化Gires-Tournois镜(编号为OGT#1)的透射率和群延迟色散，并与设计值进行了比较，分析了实测值产生偏差的原因，从而对镀膜参量进行了相应的调整，制造了第二批优化Gires—Tournois镜(编号为OGT#2)。将优化Gires—Tourn

光学薄膜元件的激光预处理技术

激光预处理技术作为一种提高激光约束核聚变装置中光学元件损伤阈值的有效方法，有重要的使用价值和学术价值。介绍了激光预处理的研究现状，重点介绍了小光斑光栅扫描预处理的方法及其应用，以及应注意的问题。讨论了几种被广泛认可的预处理增强机理，并对激光预处理技术进行了展望。

石英晶体监控膜厚仪的发展与应用

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。

The laser-assisted cold spray process

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.