8～14μm长波红外头罩材料

对比各种红外光学材料的性能认为，多晶ＺｎＳ是综合性能优良的８～１４μｍ长波红外头罩材料，概述了ＺｎＳ的制备工艺及其改进。     

长波红外玻璃的研究

长波红外玻璃具有优异的红外性能,作为视窗、透镜、整流罩等在光电技术领域中应用广泛。长波红外玻璃材料主要包括硫系玻璃、卤系玻璃和硫卤玻璃等。综述了长波红外玻璃材料的基本性能、国内外研究现状和应用,最后指出了其存在问题及发展趋势。     

红外隐身功能填料的表面改性与应用研究

简述了红外隐身的原理,从表面改性方面概述了低发射率红外隐身功能填料的制备,简要阐述了包覆技术、化学镀技术、微胶囊技术在制备低发射率红外隐身填料中的应用,并在此基础上展望了隐身材料的发展趋势.     

CVD ZnS的全球研发现状

ZnS作为重要的红外窗口光学材料应用已有40多年。CVD（化学气相沉积）法很快成为生产大尺寸ZnS窗口和头罩的制备工艺。     

宽截止长波红外带通滤光片的研制

针对空间用宽截止长波红外带通滤光片具有通带内平均透射率高、抑制带截止深度深、波纹系数小,可适应复杂环境条件,具有高稳定性和高可靠性等特点,以10.03μm～12.50μm和10.6μm～11.2μm两类宽截止长波红外带通滤光片为研究对象,论述了宽截止长波红外带通滤光片的设计原则和方法,采用"会聚光红外光学系统"和等离子体辅助沉积工艺成功镀制了空间用宽截止长波红外带通滤光片.指出等离子体辅助沉积工艺更有利于改善长波红外滤光片膜层的显微结构和残余应力消除.     

氧氟玻璃及其微晶玻璃的研究进展

介绍了氧氟玻璃的基本概念、性能特点和氧氟玻璃的成分、分析方法和性能方面的研究进展及其在红外光学材料和高能激光窗口等方面的应用,系统介绍了用作激光工作介质的掺稀土氧氟微晶玻璃的研究概况,探讨了氧氟玻璃和氧氟微晶玻璃开发研究中存在的问题和发展方向,认为氧氟玻璃在红外光学材料和高能激光窗口方面具有巨大的发展潜力和应用前景,氧氟微晶玻璃是高功率的激光工作介质的优良材料.     

一种长波红外宽光谱长波通滤光片的设计与镀制

长波红外宽光谱长波通滤光片是光谱成像技术中重要的光学元件。本文研究了一种宽光谱长波通滤光片优化设计,论述了设计长波红外宽光谱长波通滤光片的设计原则和方法。根据等效折射率理论,以周期性对称膜系为基础,使用压缩透射区内波纹幅度的部分膜层优化方法,设计了满足性能指标要求的长波红外长波通滤光片。经过优化,所设计的膜系高透射波段内的平均透射率大于90%,高透射区内的最低透射率也高于85%。截止波段内的平均透射率小于1%,截止区内的最高透射率也低于5%。研究表明,部分膜层优化方法设计的膜系,膜层结构简单,有利于膜层厚度的监控,既能克服全自动优化方法给工艺上带来的困难,又弥补了解析法设计膜系时不能调整光谱特性的不足。     

红外光学材料硫化锌概览

红外光学材料是红外技术应用的基础之一,是指红外成像和制导技术中用于制造透镜、棱镜、窗口、滤光片、整流罩等的一类材料“’。从原理上分析,当太阳光透过大气层照射到地面上,大气对红外辐射的某些波段有吸收,而对另一些波段则可透过,透过的波段称之为“大气窗口”。     

红外光谱法在金属氧化物纳米材料研究中的应用

红外光谱法是材料研究中的一种重要的分析手段.综述了红外光谱法在金属氧化物纳米材料的制备、表征、计算机模拟等方面的应用.在此基础上,指出了红外光谱法在金属氧化物纳米材料中应用的发展方向.     

新型SiC光学材料的制备及应用

随着空间成像技术的发展,当今各科技大国均加大了对新型光学材料的制备及应用的研究工作.近年来新近兴起的新型SiC材料因其良好的热稳定性、高比刚度、低密度、易于轻量化等优点,而成为未来空间相机主光学成像元件的首选材料.本文结合当前国内外SiC材料研究进展,介绍了新型SiC光学材料常用的几种制备技术及相关应用,对其制备方法和...     

卤化银光纤原料的超提纯

高纯原料的制备是制造高品质光纤最重要的环节,本文采用氯气氛下水平区熔法生长单晶的提纯方法对卤化银原料进行超提纯．区域熔融提纯后的卤化银原料红外吸收光谱测量显示在800～4000cm^－1范围内吸收随波长的增加而降低．经CO₂激光量热计法测量提纯后的卤化银原料在10．6μm处的吸收系数为5×10^－4Cm^－1,较提纯前降低两个数量级,制成的光纤传输损耗03～0．5dB／m     

Analysis of dichroic dye-doped polymer-dispersed liquid crystal materials for display devices

Dichroic polymer-dispersed liquid crystals (DPDLCs) based on nematic liquid crystal materials with azo dye were investigated in detail for the application of display devices. Polarizing optical microscopy, differential scanning calorimeter and electro-optic experiments all have shown that the DPDLC containing low concentration of dyes modifies the basic properties of these materials like optical transmission, threshold voltage, contrast ratio and absorbance factor. A minimum amount of dye needs to be added to the liquid crystal with the polymer matrix for its effective phase separation and to minimize the transmittance in the OFF state and therefore gives rise to an overall improvement in contrast ratio of the devices. Molecular orientation and dynamics in droplet sizes are readily controlled in these DPDLC materials. These findings imply that the value of the threshold electric field E_th is approximately 8 V/μm for pure polymer-dispersed liquid crystal (without dye) where the threshold electric field E_th values are approximately 4.0 V/μm, 2.0 V/μm, 1.7 V/μm 1.0 V/μm, for 0.0625%, 0.125%, 0.25% and 0.5% with azo dye in DPDLCs, respectively. From the results we can also infer that the maximum contrast is approximately 2.55 times the minimum contrast observed in the experiment for DPDLCs. The results show that the DPDLC with proscribed dye concentration will be possibly suitable and promising functional electronic materials for green technology flexible liquid crystal display.     

Chalcogenide Photonic Crystals Fabricated by Soft Imprint‐Assisted Photodoping of Silver

This work presents a low‐cost, large‐scale nanofabrication approach that combines imprint lithography and silver doping (IL‐SD) to pattern chalcogenide glass (ChG) films for realizing IR devices. The IL‐SD method involves controled photodoping of silver (Ag) atoms into ChG films and selective removing of undoped ChG. For photodoping of Ag, an Ag‐coated elastomer stamp is brought in contact with the ChG film and exposed to ultraviolet light, and subsequently, the Ag atoms are photo‐dissolved into the ChG film following the nanopatterns on the elastomer stamp. Due to the high wet‐etching selectivity of the undoped ChG to Ag‐doped one, the ChG film can be precisely patterned with a spatial resolution on the order of a few tens of nanometers. Also, by controling the lateral diffusion of Ag atoms during ultraviolet exposure, it is possible to adjust the size of the final patterns formed in the ChG film. As an application demonstration of the IL‐SD process, the As₂S₃‐based near‐infrared photonic crystals (PhCs) in the wavelength range and flexible midinfrared PhCs are formed, and their optical resonances are investigated. The IL‐SD process enables the low‐cost fabrication of ChG nanostructures on different substrate materials and gives a great promise to realize various IR devices.     

Parametric down-conversion devices: The coverage of the mid-infrared spectral range by solid-state laser sources

The development of parametric down-conversion devices operating in the mid-infrared, from 3 μm to about 20 μm, based on non-oxide nonlinear optical crystals is reviewed. Such devices, pumped by solid-state laser systems operating in the near-infrared, fill in this spectral gap where no solid-state laser technology exists, on practically all time scales, from continuous-wave to femtosecond regime. The vital element in any frequency-conversion process is the nonlinear optical crystal and this represents one of the major limitations with respect to achieving high energies and average powers in the mid-infrared although the broad spectral tunability seems not to be a problem. Hence, an overview of the available mid-infrared nonlinear optical materials, emphasizing new developments like wide band-gap, engineered (mixed), and quasi-phase-matched crystals, is also included.     

Organic Materials for Third-Order Nonlinear Optics

The current status of organic low-molecular weight and polymeric materials for third-order nonlinear optics is reviewed. The importance of organic materials lies in their promise of large nonlinear optical figure of merit, high optical damage thresholds, ultrafast optical responses, architectural flexibility, and ease of fabrication. Organic materials exhibiting interesting third-order nonlinear optical properties are discussed to illustrate the importance of structure–property correlations. Results on emerging organic materials that include liquids, dyes, fullerenes, charge-transfer complexes, π-conjugated polymers, dye-grafted polymers, organometallic compounds, composites, and liquid crystals are presented. Organic nonlinear optical materials seem promising for a wide range of applications and their potential for integrated optics should be further explored.     

Hydrocarbon vapor measurements in fuel sprays: a simplification of the infrared extinction technique

An equal optical thickness approximation that greatly simplifies the application and data reduction of the infrared extinction technique for measuring fuel vapor concentrations in sprays is investigated. A general approach is given, with specific results for a 3.39- and a 0.6328-μm-wavelength system. It is shown that the infrared (3.39-μm) drop optical thickness can be approximated by the use of the visible (0.6328-μm) optical thickness for drop size distributions with area mean diameters greater than 20 μm for hydrocarbon fuel sprays.     

Complex-shaped three-dimensional microstructures and photonic crystals generated in a polysiloxane polymer by two-photon microstereolithography

Two-photon photopolymerization of inorganic–organic hybrid materials permits the generation of complex-shaped three-dimensional microstructures at submicrometer resolution of structural elements. Due to their favorable optical, chemical and thermal properties these materials are particularly useful for photonic microdevice fabrication. Focussing ultrashort pulsed visible light into a modified commercially available polysiloxane polymer a Sydney Opera House design and a series of woodpile-type photonic crystals were fabricated. Fourier transform infrared spectroscopy revealed photonic stop gaps in the stacking direction at wavelengths varying from 6 to 4 μm upon reduction of the woodpile rod size. The structures allowed for the observation of higher-order stop gaps.     

Lu2O3-MgO纳米粉体合成及其复相红外透明陶瓷制备

细化陶瓷微观结构至纳米级, 可以减少光的散射损失, 为开发新型光学陶瓷提供了一种有效的方法。本研究采用溶胶-凝胶法合成粉体, 结合热压烧结工艺制备出光学性能优异的新型Lu₂O₃-MgO纳米复合陶瓷, 研究了粉体合成条件及热压烧结工艺对样品微观结构的影响, 并对计算的理论透过率与样品的实际透过率进行了比较。研究结果表明: 采用优化后工艺制备的Lu₂O₃-MgO陶瓷具有均匀的相域分布, 晶粒尺寸约为123 nm, 3~5 μm波段的透过率高达84.5%~86.0%, 接近理论透过率; 维氏硬度为12.2 GPa, 断裂韧性为2.89 MPa·m^-1/2, 抗弯强度达到(221±12) MPa, 是一种潜在的红外透明窗口材料。     

Infrared Refractive Index and Extinction Coefficient of Polyimide Films

We have measured the transmittance of several polyimide (C₂₂H₁₀N₂O₄) films at wave numbers from 6000 to 500 cm^–1 (wavelengths from 1.67 to 20 m) using a Fourier-transform infrared (FT-IR) spectrometer. The free-standing polyimide films are made by spin coating and thermal curing processes. The thickness of the films ranges from 0.1 to 4 m. In the nonabsorbing region from 6000 to 4000 cm^–1, the minimum transmittance caused by interference is used to obtain the refractive index for film thicknesses greater than 1 m. The film thicknesses are determined by fitting the spectral transmittance using the refractive index. Molecular absorption strongly reduces the transmittance at wave numbers from 2000 to 500 cm^–1. The optical constants, i.e., the refractive index and the extinction coefficient, are determined from the measured transmittance for several films of different thickness using a least-squares method. A Lorentzian oscillator model is also developed, which in general agrees well with the measured transmittance at wave numbers from 6000 to 500 cm^–1. This study will facilitate the application of polyimide films in the fabrication of infrared filters and other optoelectronic applications. The methods presented in this paper can be used to determine the optical constants of other types of thin-film materials.     

Fabrication of fibers with high rare-earth concentrations for Faraday isolator applications

The Faraday effect provides a mechanism for achieving unidirectional light propagation in optical isolators; however, miniaturization requires large Verdet constants. High rare-earth content glasses produce suitably large Verdet values, but intrinsic fabrication problems remain. The novel powder-intube method, or a single-draw rod-in-tube method, obviates these difficulties. The powder-in-tube method was used to make silica-clad optical fibers with a high terbium oxide content aluminosilicate core. Core diameters of 2.4 μm were achieved in 125-μm-diameter fibers, with a numerical aperture of 0.35 and a Verdet constant of -20.0 rad/(T m) at 1.06 μm. This value is greater than 50% for crystals found in current isolator systems. This development could lead to all-fiber isolators of dramatically lower cost and ease of fabrication compared with their crystalline competitors.