Results 121 to 130 of about 3,285 (273)

Coupling of Er3+ ions and Plasmonic Modes in Vertical Nanocavities for Spectral Broadening in Telecom Bands

Advanced Materials Technologies, EarlyView.
Left: Illustration of the glass & nanostructures system and the NIR emission at 1.5 µm, where the colored spheres represent the Er3+ ions within the doped glass. Right: Representation of the Stark splitting of the 4I13/2 and 4I15/2 manifolds of the Er3+, illustrating how the plasmonic modes facilitate the emission from the broader Stark manifold ...
Gaston Lozano Calderón, Víctor Anthony García Rivera, Stéphan Cagnon, Souleymane Toubou Bah, Younès Messaddeq, Euclydes Marega Junior   +5 more
wiley   +1 more source

Wideband Cyclostationary Spectrum Sensing and Modulation Classification [PDF]

, 2013
Wideband spectrum sensing is a key enabling functionality for Cognitive Radios (CRs) since it detects unoccupied bands and allows throughput increase.
Rebeiz, Eric
core  

Large Faraday Rotation in Liquid Crystals With Embedded Paramagnetic Ions (Cu2+, VO2+) at Room Temperature

Advanced Optical Materials, EarlyView.
Large Faraday rotation at room temperature is observed in thin films of discotic copper (Cu2+: 3d9) and vanadyl (VO2+: 3d1) enaminoketone complexes. The large Verdet constant originates from a high density of paramagnetic centers, metal‐ligand p−d hybridization and π orbitals involved in optical transitions (identified by DFT calculations), as well as ...
Karolina Łempicka‐Mirek, Adam Krówczyński, Mateusz Król, Nevill Gonzalez Szwacki, Paulina Rybak, Damian Pociecha, Paweł W. Majewski, Barbara Piętka, Jacek Szczytko   +8 more
wiley   +1 more source

An Improved Distributed Multi-User Cooperative Spectrum Sensing Method Based on DCS

Dianxin kexue, 2013
Distributed compressed sensing theory extends the application of compressed sensing theory, which brings single signal compression sampling to signal group compression sampling.
Jianwu Zhang, Xiaoyan Chen, Xiaorong Xu
doaj   +2 more sources

Targeted Adversarial Attacks Against Deep Learning-Based Wideband Spectrum Sensing

IEEE Transactions on Machine Learning in Communications and Networking
Deep learning-based wideband spectrum sensing models have achieved impressive performance in subband occupancy detection, but their susceptibility to adversarial attacks raises serious concerns.
Shilian Zheng, Zhihao Ye, Luxin Zhang, Keqiang Yue, Zhijin Zhao   +4 more
doaj   +1 more source

Broadband Directional Thermal Radiation with Asymmetric Femtosecond Laser‐Processed Surfaces

Advanced Optical Materials, EarlyView.
Femtosecond laser processing is used to scalably create self‐organized angled microstructures which exhibit highly directional emissivity that occurs for all polarizations. Laser parameters are tuned to alter the surface features, control the direction of emission, and enhance the directional emissivity. Electromagnetic modeling is performed to analyze
Andrew Butler, Andrew Reicks, Jack Schulz, Patrick Hayden, Alireza Kalantari Dehaghi, Kira Marr, Linxiao Zhu, Christos Argyropoulos, Craig Zuhlke   +8 more
wiley   +1 more source

Thickness‐Dependent Infrared Emissivity of Ultrathin Freestanding MoSiN Nanocomposite Membranes

Advanced Optical Materials, EarlyView.
ABSTRACT Metals and dielectrics show opposite trends in thickness‐dependent infrared emissivity: metallic films exhibit a rise in emissivity below a critical thickness, while dielectric films show a corresponding decline. For applications demanding both high emissivity and mechanical strength in membranes with nanoscale thickness, combining these ...
Reethu Sebastian, Amrid Amnache, Nadi Braidy, Luc G. Fréchette   +3 more
wiley   +1 more source

Distributed cooperative spectrum sensing based on consensus optimization

Tongxin xuebao, 2011
A distributed wideband spectrum compressive sensing approach based on consensus optimization was developed.The cognitive radio users firstly collected the time-domain sampling by compressive sampling and recover the local spectrum.Then the spectrum of ...
ZENG Fan-zi, LIU Jie, LI Ren-fa, ZENG Qing-guang   +3 more
doaj   +2 more sources

A Novel Wideband Spectrum Sensing System for Distributed Cognitive Radio Networks

, 2011
A significant challenge of cognitive radio (CR) is to perform wideband spectrum sensing in a fading environment. In this paper, a novel multi-rate sub-Nyquist spectrum detection(MSSD) system is introduced for cooperative wideband spectrum sensing in a ...
Jiang, Jing, A. Nallanathan, Wang, C.-X., Nallanathan, A, Laurenson, D.I., Cheng-Xiang Wang, Wang, C-X, H. V. Poor, Poor, H. Vincent, D. I. Laurenson, Sun, H, Nallanathan, Arumugam, Laurenson, David, Poor, HV, Jiang, J, Sun, Hongjian, Poor, H.V., Laurenson, DI, Wang, Cheng-Xiang, Nallanathan, A., Jing Jiang, Hongjian Sun, Laurenson, David I.   +22 more
core   +1 more source

Spacer‐Less Substrate‐Integrated Metasurface for Near‐Unity Terahertz Absorption

Advanced Optical Materials, EarlyView.
ABSTRACT Although conventional metal‐insulator‐metal (MIM) terahertz (THz) absorbers can provide near‐unity absorption, their multilayer stacks inevitably introduce additional thickness, mass, and residual stress, which limit their compatibility with THz thermal sensing platforms.
Zihao Zhao, Kazuho Harada, Qian Liu, Isao Morohashi, Xu Fang, Kazuhiko Hirakawa, Ya Zhang   +6 more
wiley   +1 more source