Properties of Optical Thin Films

In this review an attempt is made to look shortly into the fundamentals of optical thin films at first and to describe them more detailed by examples and applications in the second part of the paper.     

碲氧溅射薄膜的光学性质

碲氧薄膜是很有希望的可擦写光盘介质材料。本文用射频溅射技术制备碲氧系统的薄膜。测定热处理前后薄膜的光学特性(光透过率、反射率、折射指数、光吸收系数和光能隙)和 X 射线衍射特性,并研究了这些性能与靶材的组份关系,还测定了这些薄膜激光喇曼光谱,并讨论它们的结构特征。     

Fabrication of Optical Tunable Helical Thin Films

Circular polarization selection of light is an important property of helical micro-nanostructure.The helical thin films fabricated by glancing angle deposition can provide both circular polarization selection and wavelength tuning in this work.Their selective transmissions were depicted in calculations and experiments.The wavelength tuning mechanism was revealed as the relationship between peak wavelength and deposition parameters.Therefore,tunable circular polarization components can be designed according to the mechanism mentioned above and fabricated by glancing angle deposition techniques.Potential applications include tunable optical filters,optical pulse-shapers,biosensors etc.     

光学薄膜的数字滤波器设计方法

本文给出利用数字滤波器的设计方法设计光学薄膜的具体过程.由数字滤波器设计软件,按照光学薄膜的设计要求给出光学薄膜目标谱传递函数,将光学薄膜传榆矩阵表示为格型数字滤波器传输矩阵的数学形式,导出等光学厚度光学薄膜传递函数的递归关系式.利用光学薄膜传递函数递归关系,采用剥层算法计算出各膜层的折射率,得到满足目标谱传递函数的膜...     

Optical Transition in Reduced C60 Thin Films

Absorption spectra of C60 thin film reduced in an electrochemical cell are studied. The results are compared with data of chemically reduced C60 anions. Absorption with relatively broad line-width below the energy of 1 eV is observed in the film besides the peaks at 1.14 ∼ 1.4 eV observed in C60 anion solution. The electronic states of reduced COT are discussed in terms of the solid state effect.     

SmS光学薄膜研究新进展

SmS光学薄膜是一种可用于全息记录的薄膜材料,由于其特殊的结构特点,在全息记录、光学开关、压敏元件等领域具有广阔的应用前景.通过对SmS薄膜的结构特点、制备方法、相变原理和应用领域等方面的综述,提出并设计了水热法、仿生法、溶胶-凝胶法及电沉积法等制备SmS薄膜的几种湿化学方法,展望了SmS薄膜今后的研究和发展趋势.     

TeOx Thin Films for Write-Once Optical Recording Media

TeOx thin films were prepared by vacuum evaporation of TeO2 powder. Structural characteristic and surface mor-phology of the as-deposited films was analyzed by using X-ray photoelectron spectroscopy, transmission electron microscopy, X-ray diffractometer and atomic force microscopy. It was found that the films represented a two component system comprising Te particies dispersed in an amorphous TeO2 matrix. The dispersed Te particies were in a crystalline state. The TeOx films showed a finely granular structure and a rough surface. Results of the statie recording test showed that the TeOx films had good writing sensitivity for short-wavelength laser beam (514.5 nm). Primary results of the dynamic test at 514.5 nm were also reported. The TeOx films were suitable for using as a blue-green wavelength high density optical storage medium.     

Electrical and Optical Properties of GaSe Thin Films

The structure, electrical transport, and optical properties of GaSe films fabricated by means of radio-frequency (RF) magnetron sputtering in Ar were investigated. The as-sputtered GaSe films were amorphous, and their optical energy gap Eg are 1.9～2.6 eV. The effect of the synthesis conditions on the optical and electrical properties of the GaSe films has also been studied     

Nonlinear Optical Characteristics of C60 Thin Films

Abstract

The results of investigation of the real and imaginary parts of third‐order nonlinear susceptibility (χ⁽³⁾) of C₆₀ thin films (～100 nm) at the wavelength of Nd: YAG laser radiation (532 nm, τ = 55 ps) are presented using Z‐scan technique. Our studies show that the sign of Reχ⁽³⁾ changes from negative, at pulse repetition rate of 2 Hz to positive, at 0.5 Hz. Sign variations of the real part of the third‐order susceptibility were attributed to the influence of the thermal lens.     

(Pb,Ca)TiO3铁电薄膜光学性质的研究

用溶胶凝胶法在Ｓｉ（１００）衬底上制备了（Ｐｂ,Ｃａ）ＴｉＯ３铁电薄膜样品,测量了其在２．３￣５．０ｅＶ能量范围的鸫谱,并获得样品的膜厚和在该区间的光学常数谱,实验发现Ｐｂ离子被Ｃａ离子取代后,折射率向低能方向移动;同时随着Ｃａ含量的增加,（Ｐｂ１Ｃａ（ＴＩＯ３工能方向移动,表明Ｃａ离子取代Ｐｂ离子后,禁带宽度Ｅｇ减小,还了引起折射率峰移动和禁带宽度Ｅｇ减小的原因。     

Structural and Optical Properties of Co-Doped ZnO Thin Films

Co-doped zinc oxide thin films (Zn_1–xCo_xO) have been deposited on c-plane sapphire substrates by dual-beam pulsed laser deposition. The films have lattice parameters similar to that of ZnO, and the lattice parameters are closely distributed. The films grew along a preferred direction, following the epitaxial relationship Zn_1–xCo_xO (0001)substrate (0001). Excitonic emission was suppressed at higher Co-dopant concentration in ZnO because of increase in the distortion of host lattice and defects. When more Zn is replaced by Co, more impurity levels are developed within the bandgap, and more defect are generated. Under our experimental conditions, the bandgap of the films tends to increase with increasing dopant concentration.     

Optical and Electrical Properties of Nickel Xanthate Thin Films

Nickel xanthate thin films (NXTF) were successfully deposited by chemical bath deposition, on to amorphous glass substrates, as well as on p- and n-silicon, indium tin oxide and poly(methyl methacrylate). The structure of the films was analysed by X-ray diffraction (XRD), far-infrared spectrum (FIR), mid-infrared (MIR) spectrum, nuclear magnetic resonance (NMR) and scanning electron microscopy (SEM). These films were investigated from their structural, optical and electrical properties point of view. Uniform distribution of grains was clearly observed from the photographs taken by scanning electron microscope (SEM). The higher transmittance was about 50–60% after optimizing the parameters of deposition time and temperature (4 h, 50 °C). The optical bandgap of the NXTF was graphically estimated as 3·90–3·96 eV. The resistivity of the films was calculated as 62·6–90·7 Ω·cm on commercial glass depending on the film thickness and 62·2–74·5 Ω·cm on the other substrates. The MIR and FIR spectra of the films conformed to the literature and their solid powder forms. The expected peaks of nickel xanthate were observed in NMR analysis on glass. The films were dipped into chloroform as organic solvent and were analysed by NMR.     

ZnO:Cd薄膜光学性能的研究

本文以载玻片、石英为基底,采用控制掺杂方法,制备了ZnO:Cd薄膜,通过热处理方法获得了优良性能的ZnO:Cd薄膜。研究分析了镉浓度为2%-10%时ZnO薄膜的透射光谱。结果表明,有较强的紫外发射峰,但没有深能级发射,未出现其它的发射峰,说明ZnO:Cd薄膜在紫外线区的发射占主导地位,表明带间跃迁占主导地位。     

Temperature Dependence of Optical Spectra of C60 Thin Films

Abstract

We examine the temperature-induced changes of the optical spectra of thin C₆₀ films deposited on silicon and gold. We have used thermoreflectance to study the spectral response of the lowest electronic states. We have found strong effects related to the phase transition and freezing of the rotations of C₆₀ molecules upon cooling.     

Temperature Dependence of Optical Spectra of C60 Thin Films

We examine the temperature-induced changes of the optical spectra of thin C₆₀ films deposited on silicon and gold. We have used thermoreflectance to study the spectral response of the lowest electronic states. We have found strong effects related to the phase transition and freezing of the rotations of C₆₀ molecules upon cooling.     

Structural and Optical Studies on Ion-implanted 6H-SiC Thin Films

A series of hot (600 °C) and room temperature C⁺/Al⁺ co-implanted 6H-SiC epitaxial films, under different implantation dose levels and high temperature (1550 °C) post-annealing, were studied by a variety of structural and optical characterization techniques, including secondary ion mass spectroscopy, high resolution X-ray diffraction, Fourier transform infrared reflectance, micro-Raman and photoluminescence (PL) spectroscopy. The damage and amorphization of SiC layer by co-implantation, and the elimination/suppression of the implantation induced amorphous layer via high temperature annealing are observed. The recovery of the crystallinity and the activation of the implant acceptors are confirmed. The results from hot or RT co-implantation are compared.     

原子层沉积技术及其在光学薄膜中的应用

回顾了原子层沉积(ALD)技术的发展背景,通过分析ALD的基本工艺,并与传统薄膜制备工艺进行了对比研究.介绍了它在膜层的均匀性、保形性以及膜厚控制能力等方面的优势.着重列举ALD在减反膜、紫外截止膜、折射率可调的薄膜、抗激光损伤薄膜及复杂结构光子晶体等方面的应用.同时指出了目前ALD工艺在光学薄膜应用中存在的主要问题,并对ALD未来的发展进行了展望.     

Preparation of Optical Quality ZnCdTe Thin Films by Vacuum Evaporation

A procedure to make optical quality thin films of Zn(x)Cd(1-x)Te by use ofvacuum evaporation of the ternary compound has been developed. Thestarting point was the preparation of the compound that was then usedas the source in a simple vacuum evaporation system. Thecharacteristics of a film containing 85% ZnTe (x =0.85) are presented. Electron microscope, atomic forcemicroscope, x-ray and optical spectral measurements were made. Theindex of refraction was determined at room temperature fromtransmittance measurements in the range of from 580 to 800 nm and wasfound to agree within 1% with values found by others for singlecrystals. We did this by assuming a Sellmeier equation and a knownindex of refraction at infinite wavelength. The calculation alsoyielded the roughness of the film.