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针对现代光通信中的核心元件之一--密集型波分复用(DWDM)系统中极窄带光学薄膜干涉滤光片的指标要求,提出采用基于四分之一波长的规整膜系是实现密集型波分复用功能的最佳选择.对给定的设计方案的各个膜层的误差灵敏度分布、特定膜层的误差成因进行了分析,并对多个膜层进行了随机分布的误差模拟.通过对直接极值法监控中不同误差的补偿机理的研究,指出采用直接极值法监控是目前为止镀制这种滤光片的有效方法.最后讨论了可能存在的两种系统误差. 相似文献
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Funding Ge Limin Chen Jing Zhu 《International Journal of Infrared and Millimeter Waves》1996,17(1):255-268
The formulations of reflection coefficients for metal-backed one- and multi-layered chiral microwave absorbing coatings are derived in a much straight way in this paper. It is found that the propagation of normally incident plane waves in chiral coatings can be treated as in their achiral counterparts if the intrinsic impedance and wavenumber of the achiral structure are replaced by their associated chiral impedance and average chiral wavenumber, respectively. From a practical point of view, examples of one- and two-layered chiral microwave absorbing coatings are given, and the effects of the real and imaginary parts of the chiral admittance on the antireflection characteristics are examined for the first time, the results show that with a appropriate complex chiral admittance, the reduction in reflection can be enhanced and the minimum-reflection-frequency can be controlled. 相似文献
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Feding Ge Jing Zhu Limin Chen 《International Journal of Infrared and Millimeter Waves》1996,17(2):449-455
The effective parameters of chiral composite are studied using a simple model, that is, randomly oriented non-interacting wire helices embedded in a nonchiral host medium. It is found that both the effective permittivity and permeability are independent on the handedness of the chiral objects while the effective chirality admittance is dependent. It is also found that when the ratio of the radius of the chiral helix to its pitch is about 0.23, maximum chirality admittance is achieved. The effective parameters of equichiral sample are also discussed. 相似文献
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宽截止窄带高反射滤光膜设计 总被引:2,自引:1,他引:1
窄带高反射滤光膜在光通讯、光学探测仪器等领域有着重要应用.探讨了"基片|H(LH)m1aL(HL)m2βCr,M|空气"膜系结构的窄带高反射滤光膜系,讨论了金属Cr层厚度,以及两种不同的匹配膜系对滤光膜特性的影响,计算了Cr层内部的电场分布.结果表明,较厚的金属层可实现更宽的截止带宽,匹配层的加入有效地实现了宽截止带的深截止,使中心波长处导纳为较大值的匹配膜系可以更好地实现滤光膜宽截止、窄带高反射特性;匹配膜层使中心波长处Cr层内部的电场强度趋于零,有效地降低了整个膜系的吸收,提高了反射率. 相似文献
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自组织生长锗量子点的库仑荷电效应 总被引:1,自引:0,他引:1
将导纳谱应用于半导体GeSi量子点的研究,观察到了典型直径为13nm的Ge量子点的库仑荷电效应及其分立能级结构. 相似文献
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分析了不同起始情况的束流通过有横向耦合的束流系统后发射度的变化,给出了束流有效发射度的边界方程式及匹配条件. 相似文献
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Coupling transfer matrix method to finite element method for analyzing the acoustics of complex hollow body networks 总被引:1,自引:0,他引:1
This paper exposes a procedure to couple multiport transfer matrices to finite elements for analyzing the acoustics of automotive hollow body networks with a minimum of memory requirements and computational time. Generally, hollow body networks are made up from a series of elongated fluid partitions similar to ducts or waveguides. These fluid partitions generally contain complex elements: junctions, noise control elements, and cavities. The location and type of these elements in the network, mainly the noise control elements (e.g., sealing parts), may impact the noise inside a car. In the proposed hybrid method, the elongated fluid partitions are modeled with fluid finite elements. All complexities are modeled with two-port or multiport transfer matrices. The coupling of these matrices to finite elements is naturally done at the weak integral formulation stage of the acoustical problem. The coupling does not add any degrees of freedom to, nor modify, the original finite element matrix system. Consequently, changing locations and types of noise control elements in the hollow body network is fast and does not require rebuilding the finite element system. This enables optimizing the acoustics of a complex network on a desktop computer. The hybrid method is compared to experimental results on a tee-shaped hollow body networks. Good correlations are obtained. 相似文献
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