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Plasmonics is a rapidly developing field concerning light manipulation at the nanoscale with many potential applications, of which plasmonic circuits are promising for future information technology. Plasmonic waveguides are fundamental elements for constructing plasmonic integrated circuits. Among the proposed different plasmonic waveguides, metallic nanowires have drawn much attention due to the highly confined electromagnetic waves and relatively low propagation loss. Here we review the recent research progress in the waveguiding characteristics of metallic nanowires and nanowire-based nanophotonic devices. Plasmon modes of both cylindrical and pentagonal metallic nanowires with and without substrate are discussed. Typical methods for exciting and detecting the plasmons in metallic nanowires are briefly summarized. Because of the multimode characteristic, the plasmon propagation and emission in the nanowire have many unique properties, benefiting the design of plasmonic devices. A few nanowire-based devices are highlighted, including quarter-wave plate, Fabry-Prot resonator, router and logic gates. 相似文献
293.
Kun Wang Xia Guo Chennan Ye Yulong Wang Yuan Meng Xiaojie Li Prof. Maojie Zhang 《Chemphyschem》2019,20(20):2674-2682
To achieve high open-circuit voltage (Voc) and low acceptor content, the molecular design of a small-molecule donor with low energy loss (Eloss) is very important for solution-processable organic solar cells (OSCs). Herein, we designed and synthesized a new coplanar A−D−A structured organic small-molecule semiconductor with non-fused ring structure π-bridge, namely B2TPR , and applied it as donor material in OSCs. Owing to the strong electron-withdrawing effect of the end group and the coplanar π-bridge, B2TPR exhibits a low-lying highest occupied molecular orbital and strong crystallinity. Furthermore, benefiting from the coplanar molecular skeleton, the high hole mobility, balanced charge transport and reduced recombination were achieved, leading to a high fill factor (FF). The OSCs based on B2TPR : PC71BM blend film (w/w=1 : 0.35) demonstrates a moderate power conversion efficiency (PCE) of 7.10 % with a remarkable Voc of 0.98 V and FF of 64 %, corresponding to a low fullerene content of 25.9 % and a low Eloss of 0.70 eV. These results demonstrate the great potential of small-molecule with structure of B2TPR for future low-cost organic photovoltaic applications. 相似文献
294.
Optical interconnection between vertical cavity surface emitting laser (VCSEL) and PIN on fiber-embedded printed circuit board (PCB) was studied in this paper. The whole project was introduced, and the technics by traditional manufacture machine of PCB was described in detail. Model of direct coupling structure between optical transceiver and fiber was analyzed by geometrical optics, and alignment tolerances were given. Performance parameters were tested. It was shown that the advantages of this method were low insertion loss, small size, big throughput, and compatible with traditional technics. It also could have a great application in fabrication of fiber interconnection backplane. 相似文献
295.
In the sinusoidal phase modulating interferometer technique, the high-speed CCD is necessary to detect the interference signals. The reason of ordinary CCD's low frame rate was analyzed, and a novel high-speed image sensing technique with adjustable frame rate based on an ordinary CCD was proposed. And the principle of the image sensor was analyzed. When the maximum frequency and channel bandwidth were constant, a custom high-speed sensor was designed by using the ordinary CCD under the control of the special driving circuit. The frame rate of the ordinary CCD has been enhanced by controlling the number of pixels of every frame; therefore, the ordinary of CCD can be used as the high frame rate image sensor with small amount of pixels. The multi-output high-speed image sensor has the deficiencies of low accuracy, and high cost, while the high-speed image senor with small number of pixels by using this technique can overcome theses faults. The light intensity varying with time was measured by using the image sensor. The frame rate was up to 1600 frame per second (f/s), and the size of every frame and the frame rate were adjustable. The correlation coefficient between the measurement result and the standard values were higher than 0.98026, and the relative error was lower than 0.53%. The experimental results show that this sensor is fit to the measurements of sinusoidal phase modulating interferometer technique. 相似文献
296.
This paper presented development work of an in situ method for damage detection in thin-wall structures using embedded two-dimensional ultrasonic phased arrays. Piezoelectric wafer active sensors were used to generate and receive guided Lamb waves propagating in the plate-like structure. The development of a generic beamforming algorithm that does not require parallel ray assumption through using full wave propagation paths is described. A virtual beam steering method and device, the embedded ultrasonic structural radar, was implemented as a signal post-processing procedure. Several two-dimensional configurations were investigated and compared with beamforming simulation. Finally, rectangular shape arrays were developed for verifying the generic formulas and omnidirectionality. The rectangular arrays yield good directionality within the 360° full range and are able to detect damage anywhere in the entire plate. 相似文献
297.
The representation of the AC electrical data in the complex plane reveal two major classifications of the relaxation processes known as ideal (Debye) and non-ideal (non-Debye) types. The non-Debye relaxation has been empirically observed via Cole-Cole (C-C), Davidson-Cole (D-C), and Havriliak-Negami (H-N) responses. Each of these non-Debye relaxations is visualized with an equivalent circuit similar to the ideal relaxation. Both ideal and C-C relaxations reveal semicircular behavior in the complex plane while D-C and H-N relaxations deviate from the usual semicircular loci known as skewed behavior. The extracted equivalent circuit elements are essentially non-Debye for both D-C and H-N relaxations possessing complexity in the relaxation time. The analytical method of extracting these elements in conjunction with the empirical parameters of the D-C relaxation is described using conventional (real) domain and complex domain. The curve fitting procedure provided extremely small error for the complex domain analysis. The behavior of the D-C relaxation function and the depression parameter β are also discussed using ωτ=1 and ωτ≠1 corresponding to the maximum of the imaginary part of the impedance (Z*) or permittivity (ε*). 相似文献
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利用对Lü系统实施反混沌控制的方法,构建了一类关联且有多种切换方式的四维超混沌Lü系统.依据系统的分岔图确定了各个子系统都处于超混沌状态时,系统参数的取值范围.分析了超混沌Lü系统平衡点的性质、超混沌吸引子的相图和Lyapunov指数等特性,设计并实现了这类可切换超混沌Lü系统的硬件电路,利用系统选择器,同一电路可以实现多个关联子系统的功能.电路实验表明,可切换的复杂超混沌Lü系统具有丰富的动力学行为.
关键词:
超混沌Lü系统
切换
分岔图
电路实验 相似文献