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Xu X.,Northwestern Polytechnical University | Li Y.,Northwestern Polytechnical University | Wang B.,Northwestern Polytechnical University | Zhou Z.,Science and Technology on Metrology and Calibration Laboratory
Optics Letters | Year: 2015

The resonance characteristics of plasmonic metamaterials absorbers (PMAs) are strongly dependent on geometric parameters. A resistor-inductor-capacitor (RLC) circuit model has been extended to predict the resonance wavelengths and the bandwidths of multiple magnetic polaritons modes in PMAs. For a typical metallic-dielectric-metallic structure absorber working in the infrared region, the developed model describes the correlation between the resonance characteristics and the dimensional sizes. In particular, the RLC model is suitable for not only the fundamental resonance mode, but also for the second- and third-order resonance modes. The prediction of the resonance characteristics agrees fairly well with those calculated by the finite-difference time-domain simulation and the experimental results. The developed RLC model enables the facilitation of designing multi-band PMAs for infrared radiation detectors and thermal emitters. © 2015 Optical Society of America. Source

Li Y.,Northwestern University | Guo Y.,Northwestern University | Su L.,Northwestern University | Wang B.,Northwestern University | And 2 more authors.
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2013

Optical antennas hold great promise for increasing the efficiency of photovoltaics, light-emitting devices, and optical sensors1. This paper discusses one strategy to achieve frequency selective detection at mid-infrared region, which utilize the plasmonic absorption nanoantenna. The infrared devices realized by such nanoantenna array have merits such as more flexibility of frequency selectivity, and its highlights of polarization properties, which will develop increased functionality for next generation focal plane arrays2. We investigated one example of such nanoantenna devices to tune its plasmonic resonance for achieving frequency selectivity and polarization properties. We also demonstrated its multiplex band absorption, and one tactics to broaden its absorption spectrum. The broad infrared sensitivity of nanoantenna devices would enable multiplex bands infrared imaging detectors. The optical properties of such examples are simulated and measurement which shows perfect absorption in certainty frequency-band. By exploiting nanoantenna as light-harvesting and carrier generation element, plasmonic absorption nanoantenna devices would realize both polarization- and wavelength-selective detection, which would overcome the band gap limitations of existing semiconducting materials. © 2013 SPIE. Source

Yi H.,Nanjing University of Aeronautics and Astronautics | Yi H.,Science and Technology on Metrology and Calibration Laboratory | Xu B.,Nanjing University | Gao Y.-T.,Nanjing University of Aeronautics and Astronautics
Xitong Fangzhen Xuebao / Journal of System Simulation | Year: 2013

Because of the high difficulty, the long period, and the high costs of the experiment of autonomous orbit determination for navigation constellation, hardware in-the-loop simulation was used in experimental study. In order to test the performance of orbit determination algorithm, a type of hybrid simulation system was purposed using star simulator and star sensor. Compared with computer simulation, the inter-satellite orientation observation information provided by this system is closer to actual conditions and is more effective to test the performance of orbit determination algorithm. At last, the performance of orbit determination algorithm for navigation constellation was tested based on the traditional EKF using this hybrid simulation system. © Copyright. Source

Li Y.,Northwestern University | Wang B.,Northwestern University | Xu X.,Northwestern University | Su L.,Northwestern University | Zhou Z.,Science and Technology on Metrology and Calibration Laboratory
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2014

The aim of this work is to present a multi-band absorption metamaterials. One dual cross-shape perfect absorber metamaterials (PAMs) was developed to obtain multi-band spectrum at mid-infrared. The PAMs possess three distinct resonant peaks standing independently, which are attributed to the polarization sensitive excitation of plasmonic resonance. The optical parameters retrieved by S-parameters method were investigated, which provides a satisfactory qualitative description of the multiple-band spectra responses. On the other hand, the near-field plasmonic behaviors and redistribution of the electromagnetic field were probed theoretically and numerically into the PAMs structure, which also explains the observed absorption behavior of the PAMs ensemble based upon the microscopic perspective. The multiplex spectrum enables the infrared perfect absorber metamaterials (PAMs) a powerful tool for direct access to vibrational fingerprints of single molecular structure. © 2014 SPIE. Source

Du K.,Beihang University | Wang W.,Beijing Institute of Radio Measurement and Metrology | Nian F.,Beijing Institute of Radio Measurement and Metrology | Nian F.,Science and Technology on Metrology and Calibration Laboratory | And 2 more authors.
Xi Tong Gong Cheng Yu Dian Zi Ji Shu/Systems Engineering and Electronics | Year: 2016

Active millimeter-wave near-filed human imaging is a means for concealed objects detection. A method of concealed objects detection in the usage of active millimeter-wave images is presented as a result of image characteristics which include high resolution, characteristics varying in different parts of the human, imaging influenced among human, concealed objects and other objects, and difficulties in concealed objects detection. By dividing images according to human regional characteristics, this method applies image adaptive threshold segmentation and re-extraction with the mathematical morphology to detect concealed objects. The experiments of concealed objects on images of actual acquisition are conducted with a result of accurate rate 84.13% and false alarm rate 6.61%, illustrating the effectiveness and practicality of the proposed method. © 2016, Editorial Office of Systems Engineering and Electronics. All right reserved. Source

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