135 resultados para Cosmological constants


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The optical constants of two cyanine dye films that we prepared were measured with a RAP-1-type (RAP is rotating analyzer and polarizer) spectroscopic ellipsometer. Toward making a simplified model for the wafers of a recordable compact disk (CD-R), we give their optimization designs developed with the cyanine dye films. in addition, the dynamic storage performances of two sample disks were tested by our dynamic storage testing system. Measurement results of the sample disks were obtained to test and verify our film designs. (C) 2000 Optical Society of America. OCIS codes: 160.4890, 160.4760, 210.4810.

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The effective refractive index of a kind of granular composite, which consists of granular metallic and magnetic inclusions with different radius embedded in a host medium, is theoretically investigated. Results show that for certain volume fractions of these two inclusions, the negative permittivity peak shifts to low frequency and the peak value increases with increasing radius ratio of the radius of magnetic granulae to that of metallic granulae. Simultaneously, peak value of permeability decreases with the radius ratio, and value peak shifts to high frequency with increasing volume fraction of magnetic inclusion. Therefore, the radius ratio can affect the effective refractive index considerably, and it is found that by adjusting the radius ratio, the refractive index may change between negative and positive values for certain volume fractions of the two inclusions. (c) 2005 Elsevier B.V. All rights reserved.

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Smooth thin films of three kinds of azo dyes of 2-(5'-tert-butyl-3'-azoxylisoxazole)-1, 3-diketones and their copper (II)-azo complexes were prepared by the spin-coating method. Absorption spectra of the thin films on a glass substrate in the 300-600 nm wavelength region were measured. Optical constants (complex refractive index N=n+ik) and thickness of the thin films prepared on single-crystal silicon substrate in the 300-600 nm wavelength region were investigated on rotating analyzer-polarizer type of scanning ellipsometer, and dielectric constants epsilon(epsilon=epsilon(1)+i epsilon(2)), absorption coefficients alpha as well as reflectance R of thin films were then calculated. In addition, one of the copper (II)-azo complex thin film prepared on glass substrate with an Ag reflective layer was also studied by atomic force microscopy (AFM) and static optical recording. AFM study shows that the copper (II)-azo complex thin film is very smooth and has a root mean square surface roughness of 1.89 nm. Static optical recording shows that the recording marks on the copper (II)-azo complex thin film are very clear and circular, and the size of the minimal recording marks can reach 200 nm. (c) 2004 Elsevier B.V. All rights reserved.

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Thiazolyl heterocyclic azo dye and its metal (Ni2+, Co2+)-azo complexes were synthesized. Their structures were confirmed by elemental analysis, UV-VIS absorption spectra, FT-IR, H-1 NMR and MALDI-MS. The thermal properties of metal complexes were studied by DSC-TGA. The optical constants (complex refractive index N=n + ik) and thickness of the complex thin films on polished single-crystal silicon substrates were investigated on a scanning ellipsometer. Results indicate that thiazolyl metal-azo complexes possess good optical and thermal properties. They would be a promising recording medium candidate for NVD with the Super-resolution near field structure (Super-RENS) technology. (c) 2007 Elsevier B.V. All rights reserved.

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Smooth thin films of three kinds of nickel(II)-azo complexes were prepared by the spin-coating method. Absorption spectra of the thin films on K9 glass substrate in the 300-600 nn wavelength region were measured. Optical constants (complex refractive index N = n + ik) and thickness of the thin films prepared on single-crystal silicon substrate in the 300-600 nm wavelength region were investigated on rotating analyzer-polarizer type of scanning ellipsometer, and dielectric constants epsilon (epsilon = epsilon(1) + i epsilon(2)), absorption coefficients a as well as reflectance R of thin films were then calculated at 405 nm. In addition, in order to examine the possible use of nickel(II)-azo complex thin film as an optical recording medium, one of the nickel(II)-azo complex thin film prepared on K9 glass substrate with an Ag reflective layer was also studied by atomic force microscopy and static optical recording. The results show that the nickel(II)-azo complex thin film is smooth and has a root mean square surface roughness of 2.25 nm, and the recording marks on the nickel(II)-azo complex thin film are very clear and circular, and their size can reach 200 nn or less. (c) 2006 Elsevier Ltd. All rights reserved.

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合成了2-(2-氨基-6-乙氧基苯并噻唑基偶氮)-5-(N,N-二乙基氨基)三氟甲基磺酰苯胺偶氮染料(EBTDATFS)及其与乙酸镍、乙酸钴、乙酸铜、乙酸锌等金属盐鏊合的金属鏊合物。通过红外光谱、紫外-可见吸收光谱和MALDI质谱等对染料及其金属鏊合物进行了结构表征;使用旋涂方法在K9玻璃和抛光的单晶硅基片上制备薄膜;研究了镍金属鏊合物的热学性能;使用椭偏仪研究了Ni和Zn鏊合物的光学常数。结果表明:4种金属鏊合物薄膜最大吸收光谱为621-629nm,且长波边吸收峰陡峭;TGA-DSC测试结果表明镍金属鏊

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研究了激光辐照引起Ge2Sb2Te5非晶态薄膜的电/光性质变化,当激光功率为580mW时薄膜的方块电阻有四个数量级(10^7~10^3Ω/□)的突变;对电阻发生突变前、中、后的三个样品进行了XRD测试,结果表明,随着激光功率的增大,薄膜由非晶态向晶态转变,用椭偏仪测试了结构转变前、中、后三个样品的光学常数,在可见光范围内薄膜的光学常数在波长相同情况下有:n(非晶态)〉n(中间态)〉n(晶态),k(晶态)〉k(中间态)〉k(非晶态),α(晶态)〉α(中间态)〉α(非晶态),结合电阻变化曲线和XRD图谱讨论了激光辐照Ge2Sb2Te5非晶态薄膜的电/光性质变化同激光功率和结构转变之间的关系.

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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。

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Ag films with different thickness from 8.2nm to 107.2nm were prepared by DC sputtering deposition and analyzed by X-ray diffraction with the help of optimization program on computer. Microstructrue analysis shows that the films are made of fcc-Ag particles. With the increase of thickness, the mean size of Ag particles increases and the interplaner spacing decreases gradually. The optical constants computed by computer program shows that n value decreases quickly with the increasing thickness below 17.5nm and k value changes in reverse, and then go steadily when the thickness is larger than 17.5nm at the wavelength of 550mn.

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设计并镀制了193nm Al2O3/MgF2反射膜,对它们在空气中分别进行了250-400℃的高温退火,测量了样品的透射率光谱曲线和绝对反射率光谱曲线.发现样品在高反射区的总的光学损耗随退火温度的升高而下降,而后趋于饱和.采用总积分散射的方法对样品在不同退火温度下的散射损耗进行了分析,发现随着退火温度的升高散射损耗有所增加.因此,总的光学损耗的下降是由于吸收损耗而不是散射损耗起主导作用.对Al2O3材料的单层膜进行了同等条件的退火处理,由它们光学性能的变化推导出它们的折射率和消光系数的变化,从而解释了相应

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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 effects of post-deposited annealing on structure and optical properties of electron-beam evaporated Al2O3 single layers were investigated. The films were annealed in air for 1.5 h at different temperatures from 250 to 400 degrees C. The optical constants and cut-off wavelength were deduced. Microstructure of the samples was characterized by X-ray diffraction (XRD). Profile and surface roughness measurement instrument was used to determine the rms surface roughness. It was found that the cut-off wavelength shifted to short wavelength as the annealing temperature increased and the total optical loss decreased. The film structure remained amorphous even after annealing at 400 degrees C temperature and the samples annealed at higher temperature had the higher rms surface roughness. The decreasing total optical loss with annealing temperature was attributed to the reduction of absorption owing to oxidation of the film by annealing. Guidance to reduce the optical loss of excimer laser mirrors was given. (c) 2004 Elsevier B.V. All rights reserved.

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用电子束热蒸发方法在熔融石英基底上沉积了Al2O3和MgF2两种材料的单层膜,研究了两种材料的光学特性,采用光度法计算并给出了薄膜材料在180~230nm的折射率n/和消光系数k的色散曲线。以两种材料作为高低折射率材料组合,采用1/4波长规整膜系设计并镀制了193nm的高反射膜,反射膜在退火后的反射率在193nm达到96%以上。结果表明在一定工艺条件下Al2O3和MgF2两种材料能够在193nm获得较好的光学性能,适用于高反射膜的制备。

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A series of silver films with different thickness were prepared under identical conditions by direct current magnetron sputtering. The optical properties of the silver films were measured using spectrophotometric techniques and the optical constants were calculated from reflection and transmission measurements made at near normal incidence. The results show that the optical properties and constants are affected by films' thickness. Below the critical thickness of 17 nm at which Ag film forms a continuous film, the optical properties and constants vary significantly as the thickness of films increases and then tends to a stable value which is reached at 41 nm. X-ray diffraction measurements were carried out to examine the structure and stress evolution of the Ag films as a function of films' thickness. It was found that the interplanar distance of (111) orientation decreases when the film thickness increases and tends to be close to that of bulk material. The compressive strains also decrease with increasing thickness. (C) 2007 Published by Elsevier B.V.

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研究了沉积温度对热舟蒸发氟化镧薄膜结构和光学性能的影响,沉积温度从200℃上升到350℃,间隔为50℃.采用分光光度计测量了样品的透射率和反射率光谱曲线,并在此基础上进行了光学损耗、光学常数以及带隙和截止波长的计算.采用表面轮廓仪进行了表面形貌和表面粗糙度的标定,采用X射线衍射(XRD)方法测量了不同沉积温度下样品的微结构.发现在短波长波段,随着沉积温度的升高,光学损耗增加,晶粒尺寸增大,表面粗糙度略有增加.不过散射损耗在光学损耗中所占比例均很小,光学损耗的增加主要由吸收损耗引起.随着沉积温度的升高,折射率与消光系数增大,带隙变小,相对应的截止波长向长波方向移动.