红外焦平面阵列盲元检测及补偿算法

为了消除非制冷红外焦平面阵列图像盲元、改善成像质量,利用红外焦平面阵列盲元相应特性和相邻像元的相关性,提出了一种基于阈值+相邻像元检测及加窗中值补偿算法。结果表明,阈值+相邻元检测算法实现盲元误检率低、快速查找等优点;利用加窗中值的盲元补偿算法,可以使盲元图像得到明显改善,保持图像信息的完整性,同时,算法易于硬件实现。     

一种新的红外焦平面器件非均匀性校正技术研究

在分析了红外焦平面阵列响应特性的基础上,提出了一种新的基于图像配准技术的"S"型曲线正交拟合算法,对红外焦平面阵列非均匀性进行自适应校正.仿真结果表明,该方法能有效地消除CCD像元响应不一致给图像带来的干扰,得到清晰的图像.     

基于虚拟边框视场光阑的IRFPA自适应非均匀性校正算法

 非均匀性校正是提高红外焦平面阵列成像质量的关键环节.本文提出了一种基于虚拟边框视场光阑的红外非均匀性校正算法.该算法用人工神经网络对边框像元进行初始校正,形成校正虚拟边框,再根据场景信息和帧间位移,将偏置校正参数逐行逐列传递,可消除焦平面阵列全视场响应的偏置非均匀性.由于算法主要基于代数运算,运算量较低,故能根据场景信息自适应地实现快速、高效的一点校正;且不需要对成像系统进行机械结构改造,与传统代数算法相比,适应性更强.真实红外图像与仿真图像对算法的检验结果,证明了方法的有效性.     

基于多元统计特性异常的盲元检测算法

针对红外焦平面阵列（IRFPA）探测器盲元和非均匀性导致系统性能降低的问题,首先建立红外焦平面阵列的多元正态分布时序噪声模型,将盲元看作是不符合模型统计分布特性的异常像素点,游离于多元正态分布超椭球之外。其次对序列图像进行主成分分解,将统计距离与等分线空间角作为异常像素检测的统计判据。最后,利用红外热像仪采集了黑体的序列图像数据,用于盲元检测算法的性能验证,实验结果证明该算法的有效性。     

基于滑动窗口的红外焦平面阵列盲元检测算法研究

由于红外焦平面阵列成像存在盲元等一系列问题,为了减少盲元对红外图像的干扰,本文提出一种基于滑动窗口的红外焦平面阵列盲元检测算法。对像元进行加窗并计算其中的均值中值以及一级梯度等数值,再进行加权计算并设定阈值与原像元对比进行盲元检测,最后使用局部中值滤波算法进行盲元补偿。仿真结果表明此种方法可以有效地检测盲元,拥有比较好的盲元补偿结果,有效地改善了红外焦平面阵列成像质量。     

红外探测器非均匀性校正系统研制

分析了红外焦平面阵列（IRFPA）基于定标的非均匀性校正算法和基于场景的非均匀性校正算法的优势和不足。针对红外焦平面阵列二元非线性的非均匀性理论模型这一特点,提出了一种基于S曲线拟合的校正算法。利用FLIR公司的长波非制冷红外探测器进行信号采集,建立了焦平面探测元的响应模型。描述了基于FLIR长波非制冷红外探测器在FPGA平台的处理流程,并实现了S曲线校正算法,提高了红外图像的质量。实验表明,经过S曲线拟合校正处理,减弱了红外图像的条纹噪声,使IRFPA组件的非均匀性从6.45%降低至2.06%。     

红外焦平面阵列非均匀性实时校正研究

针对红外焦平面阵列非均匀性多点校正过程中涉及的数据量大,难于实现实时校正的特点,提出了利用TMS320DM642 DSP硬件对红外焦平面阵列进行多点实时校正.利用DSP的硬件乘法器和加法器能够高速有效地实现红外焦平面阵列的非均匀性校正.实验结果表明利用DSP实现红外焦平面阵列实时非均匀性校正方法简单灵活,图像效果理想,能够很好地满足红外焦平面阵列成像系统实时性能的要求.     

一种提高红外焦平面阵列成像质量的有效方法

为了提高红外焦平面阵列的成像质量,提出一种对红外焦平面阵列的非均匀性校正的同时进行图像增强处理的方法(简称校正增强法),该方法通过对红外焦平面阵列的校正来减少各阵列元响应的非均匀性,通过对红外图像进行增强处理来提高整幅图像的对比度,从而有效地提高红外成像系统的成像质量.实验结果表明:经过校正增强方法处理后的红外图像清晰、视觉效果理想.     

双边滤波直方图均衡的非均匀性校正算法

针对传统的红外焦平面自适应校正算法存在的目标退化和收敛时间较长等问题,提出了一种融合双边滤波机制的直方图均衡红外焦平面非均匀性自适应校正方法。研究了红外焦平面响应特性,建立红外焦平面阵列响应的统计模型,根据模型首先计算单个像元的时域统计直方图,接着融合双边滤波机制求取邻域像元时域直方图的均值,最后利用该均值直方图均衡完成非均匀性校正。实际应用证明,该算法具有校正精度高、收敛速度快、抑止目标退化能力强的优点。     

红外焦平面阵列非均匀性校正的改进神经网络算法

非均匀性校正是红外焦平面阵列应用中的关键技术之一。神经网络算法是比较传统的非均匀性校正算法,由于该算法采用像元四邻域的平均值作为此像元的真值,所以这种估计方法具有较大的误差。在传统的神经网络算法基础上对焦平面阵列像元响应的真值估计进行了改进:基于图像匹配算法,采用了相邻多帧图像中不同像元对同一场景点的响应的均值作为真值,因而具有更高的准确性。对比仿真试验的结果表明,该改进算法比传统的神经网络算法具有更好的效果,在有效去除各种非均匀性的同时,保持了图像细节,改善了图像的视觉效果。     

Development of the readout system for waveguide multilayer optical card

Waveguide multilayer optical card （WMOC） is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling ＆ processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic （VB） language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor.     

Nanoimprint Lithography -A Next Generation High Volume Lithography Technique

IntroductionNanoimprint Lithography is a well-acknowl-edged low cost, high resolution, large area pattern-ing process. It includes the most promising methods,high-pressure hot embossing lithography (HEL) [2],UV-cured imprinting (UV-NIL) [3] and micro contactprinting (m-CP, MCP) [4]. Curing of the imprintedstructures is either done by subsequent UV-lightexposure in the case of UV-NIL or by cooling downbelow the glass transition temperature of the ther-moplastic material in case of HEL…     

Collinear phase-matching study of terahertz-wave generation via difference frequency mixed in GaAs and Inp

The collinearly phase-matching condition of terahertz-wave generation via difference frequency mixed in GaAs and InP is theoretically studied. In collinear phase-matching, the optimum phase-matching wave hands of these two crystals are calculated. The optimum phase-matching wave bands in GaAs and lnP are 0.95-1.38μm and 0.7-0.96μm respectively. The influence of the wavelength choice of the pump wave on the coherent length in THz-wave tuning is also discussed. The influence of the temperature alteration on the phase-matching and the temperature tuning properties in GaAs crystal are calculated and analyzed. It can serve for the following experiments as a theoretical evidence and a reference as well.     

Effects of the alloy compositions on the phonon-polaritons in ternary mixed crystals

Composition dependence of bulk and surface phonon-polaritons in ternary mixed crystals are studied in the framework of the modified random-element-isodisplacement model and the Bom-Huang approximation. The numerical results for Several Ⅱ - Ⅵ and Ⅲ- Ⅴ compound systems are performed, and the polariton frequencies as functions of the compositions for ternary mixed crystals AlxGa1-xAs, GaPxAS1-x, ZnSxSe1-x, GaAsxSb1-x, GaxIn1-xP, and ZnxCd1-xS as examples are given and discussed. The results show that the dependence of the energies of two branches of bulk phonon-polaritons which have phonon-like characteristics, and surface phonon-polaritons on the compositions of ternary mixed crystals are nonlinear and different from those of the corresponding binary systems.     

Influence of PVK ： NPB hole transporting layer on the characteristics of organic light-emitting devices

A doping system consisting of NPB and PVK is employed as a composite hole transporting layer （CHTL）. By adjusting the component ratio of the doping system, a series of devices with different concentration proportion of PVK ： NPB are constracted. The result shows that doping concentration of NPB enhances the competence of hole transporting ability, and modifies the recombination region of charge as well as affects the surface morphology of doped film. Optimum device with a maximum brightness of 7852 cd/m^2 and a power efficiency of 1.75 lm/W has been obtained by choosing a concentration proportion of PVK ： NPB at 1：3.     

New insert layer structure OLEDs

An insert layer structure organic electroluminescent device（OLED） based on a new luminescent material （Zn（salen）） is fabricated. The configuration of the device is ITO/CuPc/NPD/Zn（salen）/Liq/LiF/A1/CuPc/NPD/Zn（salen）/Liq/LiF/A1. Effective insert electrode layers comprising LiF（1nm）/Al（5 nm） are used as a single semitransparent mirror, and bilayer cathode LiF（1 nm）/A1（100 nm） is used as a reflecting mirror. The two mirrors form a Fabry-Perot microcavity and two emissive units. The maximum brightness and luminous efficiency reach 674 cd/m^2 and 2.652 cd/A, respectively, which are 2.1 and 3.7 times higher than the conventional device, respectively. The superior brightness and luminous efficiency over conventional single-unit devices are attributed to microcavity effect.     

Analysis of error performance on Turbo coded FDPIM

Due to variable symbol length of digital pulse interval modulation（DPIM）, it is difficult to analyze the error performances of Turbo coded DPIM. To solve this problem, a fixed-length digital pulse interval modulation（FDPIM） method is provided. The FDPIM modulation structure is introduced. The packet error rates of uncoded FDPIM are analyzed and compared with that of DPIM. Bit error rates of Turbo coded FDPIM are simulated based on three kinds of analytical models under weak turbulence channel. The results show that packet error rate of uncoded FDPIM is inferior to that of uncoded DPIM. However, FDPIM is easy to be implemented and easy to be combined, with Turbo code for soft-decision because of its fixed length. Besides, the introduction of Turbo code in this modulation can decrease the average power about 10 dBm, which means that it can improve the error performance of the system effectively.     

A method for calculating the center position of collimated light

It is a key problem to accurately calculate beam spots＇ center of measuring the warp by using a collimated laser. A new method, named double geometrical center method （DGCM）, is put forward for the first time. In this method, a plane wave perpendicularly irradiates an aperture stop, and a charge couple device （CCD） is employed to receive the diffraction-beam spots, then the geometrical centers of the fast and the second diffraction-beam spots are calculated respectively, and their mean value is regarded as the center of datum beam. In face of such adverse instances as laser intension distributing defectively, part of the image being saturated, this method can still work well. What＇s more, this method can detect whether an unacceptable error exits in the courses of image receiving, processing and calculating. The experimental results indicate the precision of this method is high.     

Resolution Enhancement Technology:Integrated Process Solutions using OPC

DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.     

Preparation and Characterization of TaN ALD Precursors

High purity organic-tantalum precursors for thin film ALD TaN were synthesized and characterized.Vapor pressure and thermal stability of these precursors were studied.From the vapor pressure analysis,it was found that TBTEMT has a higher vapor pressure than any other published liquid TaN precursor,including TBTDET,TAITMATA,and IPTDET.Thermal stability of the alkyl groups on the precursors was investigated using a 1H NMR technique.The results indicated that the tertbutylimino group is the most stable group on TBTDET and TBTEMT as compared to the dialkylamido groups.Thermal stability of TaN precursors decreased in the following order:TBTDET ＞ PDMAT ＞ TBTEMT.In conclusion,precursor vapor pressure and thermal stability were tuned by making slight variations in the ligand sphere around the metal center.