沉积参量及时效时间对SiO2薄膜残余应力的影响

SiO2薄膜由电子束蒸发方法沉积而成。用GPI数字波面光学干涉仪测量了不同沉积条件下玻璃基底镀膜前后曲率半径的变化，并确定了SiO2薄膜中的残余应力。在其他条件相同的情况下，当沉积温度由190℃升高到350℃时，SiO2薄膜中的压应力由一156MPa增大为-289MPa。氧分压由3．0×10^-3Pa升高到13．0×10^-3Pa时，SiO2薄膜中的应力由-223．5MPa变为20．4MPa。通过对薄膜折射率的测量，发现薄膜的堆积密度随沉积条件的改变也发生了规律性的变化。应力的变化主要是由于沉积时蒸发粒子

微缺陷对薄膜滤光片环境稳定性的影响

用热蒸发方法沉积了薄膜滤光片．并将样品分别在去离子水中浸泡10天和30天．通过分光光度计、光学暗场显微镜、及扫描电子显微镜等多种测试手段，对诱导透射滤光片在潮湿环境下的稳定性进行了研究．实验发现，在潮湿环境下滤光片产生的膜层分离都是从薄膜中微缺陷点处开始发生和发展的，微缺陷是影响滤光片环境稳定性的重要原因之一，其中杂质和针孔是滤光片中两种最常见的微缺陷．EDS能谱分析进一步表明，薄膜中杂质缺陷成分即为Al2O3膜料本身，所以不能推测，薄膜沉积中的喷溅可能是微缺陷产生的根本原因，抑制喷溅可以有效提高薄膜滤光

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.

脉宽压缩光栅用的多层膜设计和性能分析

应用于啁啾脉冲放大技术中的脉宽压缩光栅是基于多层膜作为基底，利用全息干涉技术和离子束技术刻蚀而成。脉宽压缩光栅的衍射效率和抗激光损伤阈值一方面依赖于光栅结构的设计，另一方面很大程度上取决于作为基底的多层膜的设计。给出了以413．1nm作为写入波长，1053nm作为使用波长的多层介质光栅膜的设计．样品在ZZS-800F、型真空镀膜机上采用电子束蒸发方式沉积而成，并给出了膜系结构对光学性能影响因素的详细分析，结果表明膜系H3L(H2L)^9H0．5L2．03H满足光栅膜的指标。给出了样品光学特性测试，其使用波

Nonpolarizing and polarizing filter design

We describe a nonpolarizing filter design at oblique incidence and a polarizing filter design at normal incidence that use a uniaxially anisotropic layer. The phase thicknesses and the optical admittances of 14 the layers are compensated for by the birefringent properties of a thin film at oblique incidence. This concept can be applied to the design of nonpolarizing bandpass and edge filters at oblique incidence and of polarizing beam splitters at normal incidence. Besides, the dependence of narrow-bandpass filters on normal incidence is discussed. (c) 2005 Optical Society of America.

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。

Overcoat dependence of laser-induced damage threshold of 355 nm HR coatings

A series of HR coatings, with and without overcoat, were prepared by electron beam evaporation using the same deposition process. The laser-induced damage threshold (LIDT) was measured by a 355 nm Nd:YAG laser with a pulse width of 8 ns. Damage morphologies of samples were observed by Leica-DMRXE Microscope. The stress was measured by viewing the substrate deformation before and after coatings deposition using an optical interferometer. Reflectance of the samples was measured by Lambda 900 Spectrometer. The theoretical results of electric field distributions of the samples were calculate by thin film design software (TFCalc). It was found that SiO2 overcoat had improved the LIDT greatly, while MgF2 overcoat had little effect on the LIDT because of its high stress in the HR coatings. The damage morphologies were different among HR coatings with and without overcoats. (c) 2005 Elsevier B.V. All rights reserved.

Form Birefringence in thin films with oblique columnar structures

Effective medium theory is useful for designing optical elements with form birefringent subwavelength structures. Thin films fabricated by oblique deposition are similar to the two-dimensional surface relief subwavelength gratings. We use the effective medium theory to calculate the anisotropic optical properties of the thin films with oblique columnar structures. The effective refractive indices and the directions are calculated from effective medium theory. It is shown that optical thin films with predetermined refractive indices and birefringence may be engineered.

Y2O3 stabilized ZrO2 thin films deposited by electron beam evaporation: Structural, morphological characterization and laser induced damage threshold

Four kinds of Y2O3 stabilized ZrO2 (YSZ) thin films with different Y2O3 content have been prepared on BK7 substrates by electron-beam evaporation method. Structural properties and surface morphology of thin films were investigated by X-ray diffraction (XRD) spectra and scanning probe microscope. Laser induced damage threshold (LIDT) was determined. It was found that crystalline phase and microstructure of YSZ thin films was dependent on Y2O3 molar content. YSZ thin films changed from monoclinic phase to high temperature phase (tetragonal and cubic) with the increase of Y2O3 content. The LIDT of stabilized thin film is more than that of unstabilized thin films. The reason is that ZrO2 material undergoes phase transition during the course of e-beam evaporation resulting in more numbers of defects compared to that of YSZ thin films. These defects act as absorptive center and the original breakdown points. (c) 2006 Elsevier B.V. All rights reserved.

飞秒激光用多层介质膜脉宽压缩光栅的设计

以薄膜光学的干涉理论和衍射光学的傅里叶模式理论为基础，给出了0．8μm飞秒激光器用多层介质膜脉宽压缩光栅的理论设计；设计采用H3L（HL）^9H0．5L2．4H的多层介质膜为基底，当刻蚀后表面浮雕结构的占宽比为0．35，线密度为1480线／mm，槽深为0．2μm，顶层HfO2的剩余厚度为0．15μm时，对于Littrow角度（36．7°）和TE波模式入射的衍射光栅其-1级衍射效率达到95％以上．

Design and fabrication of color filters for projection display system

Color filters are key components in an optical engine projection display system. In this paper, a new admittance-matching method for designing and fabricating the high performance filters is described, in which the optimized layers are limited to the interfaces between the stack (each combination of quarter-wave-optical-thickness film layers is called a stack) and stack, or between stack and substrate, or between stack and incident medium. This method works well in designing filters containing multiple stacks such as UV-IR cut and broadband filters. The tolerance and angle sensitivity for the designed film stacks are analyzed. The thermal stability of the sample color filters was measured. A good result in optical performance and thermal stability was obtained through the new design approach. (c) 2006 Society of Photo-Optical Instrumentation Engineers.

High-reflectance 193 nm Al2O3/MgF2 mirrors

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.

利用等效层的消偏振宽带减反膜设计

分析了倾斜入射条件下导致光学薄膜产生偏振的原因, 针对不同偏振态的等效导纳与等效相位进行了分析, 并计算了对称膜层在45°入射条件下不同偏振态的等效折射率与等效相位厚度, 采用等效层方法设计了光学性能良好的600～900 nm波段消偏振宽带减反膜。最后利用电子束蒸发技术制备了薄膜样品, 样品的光谱性能完全能够满足使用要求。其中在600～900 nm波段范围内, 平均反射率均小于1.38%, 反射率的偏振度均低于0.89％。另外, 通过对其理论及实验光学性能、角度敏感性、膜层厚度误差敏感性等方面的分析结果可

Y_2O_3稳定ZrO_2薄膜的结构和光学特性

用电子束蒸发法制备出四种不同Y2O3含量的Y2O3稳定ZrO2（YSZ）薄膜,用X射线衍射和透射光谱测定薄膜的结构和光学性能.结果表明：随着Y2O3含量的增加,ZrO2薄膜从单斜相向高温相（四方相和立方相）转变,获得了结构稳定的YSZ薄膜;YSZ薄膜的晶粒尺寸都比ZrO2薄膜的大,但随着Y2O3加入量的增加,晶粒尺寸有减小的趋势,薄膜表面也趋向光滑平整.所有YSZ薄膜的透射谱线都与ZrO2薄膜相似,在可见光和红外光区都有较高的透过率.Y2O3的加入还可以改变薄膜的折射率,在一定范围内可得到所需的任意折射率

两种后处理方法对HfO2薄膜性能的影响

利用电子束蒸发和光电极值监控技术制备了氧化铪薄膜，并分别用两种后处理方法（空气中退火和氧等离子体轰击）对样品进行了处理．然后，对样品的透过率、吸收和抗激光损伤阈值进行了测试分析．实验结果表明，两种后处理方法都能不同程度地降低了氧化铪薄膜的吸收损耗、提高了抗激光损伤阈值．实验结果还表明，氧等离子体轰击的后处理效果明显优于热退火，样品的吸收平均值在氧等离子体后处理前后分别为34．8ppm和9．0ppm，而基频（1 064nm）激光损伤阈值分别为10．0J／cm^2和21．4J／cm^2．