Broadband interference filters

The characteristics of two-component broadband interference filtering coatings are calculated for the middle-infrared spectral range. Up to now, these characteristics have been obtained only for four-component interference coatings.     

ICP-AES测定室内装饰装修用水性墙面涂料中可溶性重金属Pb,Cd,Cr

通过样品中共存元素干扰和酸度效应的研究 ,采用干扰系数法和标准加入法分别校正了光谱重叠干扰和非光谱干扰 ,建立了ICP AES测定水性墙面涂料中可溶性重金属铅、镉和铬的方法。该方法准确 ,检出限低 ,适用于水性墙面涂料的检验工作     

Enhancing the Resistance of Spectral Characteristics of Interference Coatings to Deviation in Parameters of Layers Entering into Their Composition

A new method of enhancing the resistance of spectral characteristics of interference coatings to deviations in parameters of layers entering into their composition is presented. The spectral characteristic that can be obtained using this method for the energy transmittance (or reflectance) of an experimentally manufactured coating is maximally close to the characteristic of the synthesized coating. A way to use several samples for monitoring the thickness of layers during the process of their formation with the aim to reduce the deviation of optical layers during manufacturing of interference coatings is presented.

     

磁控溅射制备微球表面金属Mo涂层的研究

利用磁控溅射制备了各种工艺参数不同的微球表面金属Mo涂层样品,并通过白光干涉仪和扫描电子显微镜对样品的表面及剖面进行了系统的测试分析。分别探究了溅射工作气压和沉积制备时间对微球表面Mo涂层表面形貌以及结晶质量的影响规律。结果表明通过优化工艺参数可制备微球直径约为800μm、涂层厚度为3.5μm到14.1μm、厚度均匀性良好的微球表面Mo涂层。Mo涂层中的晶粒呈现出柱状结构致密堆积在一起,且随涂层的厚度增加晶粒间空隙增大。     

温度对涂有溶胶-凝胶多层干涉膜的卤钨灯光谱的影响

本文叙述了两个问题.首先,采用溶胶-凝胶浸渍水解法在H4汽车灯上制备了多层干涉膜.该膜层温度升高使这种灯透过膜层的光谱有所移动,于是引起灯发射光谱的变化.其次,我们研究了温度对膜材料光学性质的影响.     

Fourier expansions for the interference film

If the calculation of the squares of the moduli of complex amplitudes is suitably performed in the theory of multiple-beam interference, infinite trigonometric series are obtained, which may be regarded as Fourier expansions of the energy formulae for reflectivity and transmissivity. From this one can directly derive a number of general properties of the interference film of a dielectric, even when metallic coatings are provided at the boundaries.Delivered in the optical section of the 1st Congress of Czechoslovak Physicists, Prague, September 1957.     

Study of optical constants of PbTe and GeTe films

Results of studying the absorption coefficients and refractive indices of PbTe and GeTe films in the spectral range from 1 to 15 μm are presented. The optical constants of films were found by a technique that combines calculation methods and the presence of strong absorption bands in the spectra. The spectral intervals were determined where the film-forming materials under consideration offer promise in the production of interference coatings for the IR spectral region.     

用溶胶-凝胶光学干涉膜改善白炽灯的发射光谱

叙述了为交通照明开发的卤钨白炽灯.这种灯涂有多层干涉膜,可用于雾灯、高色温灯、信号灯等给出了膜系设计,介绍了涂有这种膜的灯的特性和实验结果.     

Cascaded long-period gratings with nanostructured coatings

The response of the transmission spectrum of cascaded long period gratings (LPGs) to the deposition of nanostructured coatings by use of the Langmuir-Blodgett technique is investigated. The phase of the interference fringes within the LPGs' attenuation bands is shown to be highly sensitive to the optical thickness of the coating, for thicknesses of the order of 100 nm.     

Sol-gel preparation and characterization of nanoporous ZnO/SiO2 coatings with broadband antireflection properties

Nanoporous ZnO/SiO₂ bilayer coatings were prepared on the surface of glass substrates via sol-gel dip-coating process. The structural, morphological and optical properties of the coatings were characterized. The refractive indices of ZnO layer and SiO₂ layer are 1.34 and 1.21 at 550 nm, respectively. The transmittance and reflectance spectra of the coatings were investigated and the broadband antireflection performance of the bilayer structure was determined over the solar spectrum. The solar transmittances in the range of 300-1200 nm and 1200-2500 nm are increased by 6.5% and 6.2%, respectively. The improvement of transmittance is attributed to the destructive interference of light reflected from interfaces between the different refractive-index layers with an optimized thickness. Such antireflection coatings of ZnO/SiO₂ provide a promising route for solar energy applications.     

Structure and Microwave Absorbing Properties of Fe Particle Containing Alumina Prepared by Micro-arc Oxidation

Electromagnetic wave absorbing materials are being investigated as anti-electromagnetic interference coatings in self-concealing technology, and properties such as dielectric loss, conductive loss, and magnetic loss have been reported in the literature. These materials include metal oxides, alloy-epoxy composites, and especially metallic magnetic materials which have generated particular interest.     

Interference filters

An account is given of the application of thin-film interference to the production of both anti-reflection and high-reflection coatings on glass, and the more recent developments of multiple-film, Fabry-Perot, and frustrated total internal reflection filters. Applications include the 'cold mirror' which reflects visible light and transmits infra-red, and the 'dichroic mirror' used for colour separation in the colour television camera which is described briefly.     

溶胶-凝胶TiO2和SiO2光学膜的结构

本文研究了TiO₂和SiO₂溶胶-凝胶光学膜在低温热处理下的组分、形貌特征、光散射特性.AES分析结果表明,在TiO₂膜和SiO₂膜的交界面处,Ti和Si相互扩散,从而证实了在多层膜中,膜层之间、膜层和基底之间有Ti-O-Si(或Si-O-Ti,或Si-O-Si)化学键形成.AES和ESCA分析结果显示溶胶-凝胶膜经过低温处理后C的含量较高,这归结为溶胶—凝胶膜的工艺特点.AFM测试结果显示,溶胶—凝胶TiO₂光学膜的表面形貌具有显著的柱状结构,薄膜表面起伏大约是7.5nm.TiO₂,SiO₂单层膜的表面散射率随着热处理温度的提高而变大,对于不同陈化时间的溶液镀制的膜有不同的表面散率.     

A reflection interferometer with transmission-like characteristics as an element of interferometric gravitational wave detectors

It is proposed to replace the Fabry-Perot interferometers incorporated into the combined Fabry-Perot-Michelson interferometer (FPMI) by transmission-like reflection interferometers (TRIs), creating bright (transmission-like) interference fringes in the reflected light. TRIs employ asymmetric metal-dielectric mirrors with a “matching” absorbing layer. The calculations show that the shot noise-limited sensitivity of an FPMI with TRIs is nearly as high as that of a conventional FPMI (for the same quality of dielectric coatings). In the presence of scattered light or when the laser and interferometer modes are not coupled well enough, the new version of the FPMI offers considerable advantages due to the mode-filtering properties of a TRI.     

Laser-induced damage of 1064-nm narrow-band interference filters under different laser modes

The laser-induced damage behavior of narrow-band interference filters was investigated with a Nd:YAG laser at 1064 nm under single-pulse mode and free-running laser mode.The absorption measurement of such coatings has been performed by surface thermal lensing(STL)technique.The relationship between damage morphology and absorption under the two different laser modes was studied in detail.The explanation was given by the standing-wave distribution theory.     

Capping layers for extreme-ultraviolet multilayer interference coatings

The reflectivity of extreme-ultraviolet thin-film multilayer (ML) interference coatings, terminated by a native oxide or other capping layer (CL), is critically dependent on the thickness of the final deposited layer of the top period. We show in this numerical study that, for a molybdenum-silicon ML, a high reflectivity loss may be incurred if the final Si layer is not of optimum thickness. For maximum reflectivity the thickness of the final Si layer must be controlled such that the node of the standing wave lies within the absorptive CL.The final Si layer may be replaced, at the expense of reflectivity, by SiC and capped with another inert material for improved protection of the ML.     

The physics of pyroelectric infrared devices

The absorption of radiation with pyroelectric detectors and the thermal properties of these devices are discussed using a simple physical picture — the physics of waves. Considered are the reflection, transmission and interference of electromagnetic and of thermal waves within the pyroelectric sensor arrangement. In particular, thin metal films, quarter wavelength structures, and anti-reflection coatings on metal films as absorber structures are discussed. The effect of the substrate on the pyroelectric response is treated and new figures of merit are introduced for the comparison of sensor materials which are mounted on a heat sink.     

Fiber-optic Michelson interferometer fixed in a tilted tube for direction-dependent ultrasonic detection

A fiber-optic interferometer is proposed and demonstrated experimentally for ultrasonic detection. The sensor consists of a compact Michelson interferometer (MI), which is fixed in a tilted-tube end-face (45°). Thin gold films are used for the reflective coatings of two arms and one of the interference arms is etched serving as the sensing arm. The spectral sideband filter technique is used to interrogate the continuous and pulse ultrasonic signals (with frequency of 300 KHz). Furthermore, because of the asymmetrical structure of the sensor, it presents strong direction-dependent ultrasonic sensitivity, such that the sensor can be considered a vector detector. The experimental results show that the sensor is highly sensitive to ultrasonic signals, and thus it can be a candidate for ultrasonic imaging of seismic physical models.     

Laser-induced damage of Ta2O5/SiO2 narrow-band interference filters under different 1064 nm Nd:YAG laser modes

The laser-induced damage (LID) behavior of narrow-band interference filters was investigated with a Nd:YAG laser at 1064 nm under single-pulse mode and free-running mode. The absorption measurement of such coatings was performed with surface thermal lensing (STL) technique. The damage morphologies under the two different laser modes were also studied in detail. It was found that all the filters exhibited a pass-band-center-dependent absorption and laser-induced damage threshold (LIDT) behavior, but the damage morphologies were diverse. The explanation was given with the analysis of the electric field distribution and the operational behavior of the irradiation laser.     

折射率色散效应对晶体硅太阳电池反射率的影响

为了分析色散效应对晶体硅太阳电池反射率的影响,在考虑材料折射率色散效应的情况下,运用光学干涉矩阵计算了具有SiO2单层减反射膜和MgF2/ZnS双层减反射膜晶体硅太阳电池的反射率与波长的函数关系,并与实验结果和未考虑色散效应的计算结果进行了对比分析.结果表明：考虑折射率色散效应的计算结果与实验测量数据完全相符,而未考虑折射率色散效应的计算结果与实验测量数据相差较大,最大差值分别为21.5％和16.9％.