Results 71 to 80 of about 2,722 (251)

Electrohydrodynamically Driven Broadband and Color‐Shifting in Cholesteric Liquid Crystals

Advanced Optical Materials, EarlyView.
Ion‐driven electrohydrodynamic effects enable dynamic photonic bandgap modulation in cholesteric liquid crystals under low‐frequency AC driving. By regulating ion‐mediated disturbance of the helical structure, this approach produces two reversible optical responses: rapid color shifting across the visible spectrum and broadband reflection spanning the ...
Cheng‐Kuan Wu, Jin‐Yu Chen, Li‐Min Chang, Cheng‐Chang Li, Kuan‐Wu Lin, Duan‐Yi Guo, Tsung‐Hsien Lin   +6 more
wiley   +1 more source

Spectral Condensing of All‐Dielectric Structural Colors via Cascaded Formation of Self‐Similar Beams

Advanced Optical Materials, EarlyView.
Standalone low‐index microscale ridges (MRs) are promising platforms for all‐dielectric structural color generation. They are compact and easy to fabricate, but their color purity trails behind that of resonator‐ or periodic pattern‐based structural color pixels.
Rabiul Islam Sikder, Jaeyoun Kim
wiley   +1 more source

Strategy optimization method based on UAVs-assisted detection of covert communication

ETRI Journal
Unmanned aerial vehicles (UAVs) are highly mobile and easily deployabledevices that have become an important component of wireless communica-tion countermeasures.
Xiaohan Wang, Wen Tian, Guangjie Liu, Yuwei Dai   +3 more
doaj   +1 more source

Flexible and Scalable 2D/3D Tin‐Based Perovskite Photodetectors via Inkjet Printing

Advanced Optical Materials, EarlyView.
Lead‐free tin‐based perovskite films are successfully fabricated via scalable inkjet printing on rigid and flexible substrates. Incorporating high‐purity precursors and dual‐layer encapsulation minimizes defects and eliminates oxidation. The resulting photodetectors demonstrate high responsivity, persistent photoconductivity, and excellent 30 day ...
Giovanni Vescio, Vladimir S. Chirvony, Isaac Suárez, Sandra Soriano, Jesús Sanchez‐Diaz, Wiktor Żuraw, Łukasz Przypis, Senol Öz, Kenneth Lobo, Sergi Hernández, Albert Cirera, Iván Mora‐Seró, Blas Garrido, Juan P. Martínez‐Pastor   +13 more
wiley   +1 more source

Exploiting High Millimeter Wave Bands for Military Communications, Applications, and Design

IEEE Access, 2019
Military communications networks can leverage much of the millimeter-wave (mm-wave) technology being investigated and developed for 5G cellular but require special attention to the unique military requirements.
James F. Harvey, Michael B. Steer, Theodore S. Rappaport   +2 more
doaj   +1 more source

Programmable Anisotropic Terahertz Permittivity via High‐Aspect‐Ratio 3D‐Printed Dielectric Mesh Networks

Advanced Optical Materials, EarlyView.
A 3D‐printed Terahertz (THz) anisotropic dielectric with programmable permittivity by varying infill density and creating high‐aspect‐ratio channels is presented. The proposed design was evaluated both experimentally, through THz time‐domain spectroscopy, and theoretically, through FDTD simulations and Effective Medium Theory analysis.
Chi Him Liu, Hwan Sik Kim, Andre Sarker Andy, Imad A.M. Ahmed, Yeong Hwan Ahn, Sang‐Soo Chee, Mira Naftaly, John E. Cunningham, Sae June Park   +8 more
wiley   +1 more source

Community Covert Communication - Dynamic Mass Covert Communication Through Social Media

CoRR
22 pages, 8 figures, this work has been presented at 44CON 2024 & 44CON 2025 in ...
openaire   +2 more sources

1.5 µm Emission Properties of Erbium‐Implanted Thin‐Film Lithium Niobate

Advanced Optical Materials, EarlyView.
Optically active Er3+ ions are incorporated into x‐cut lithium niobate on insulator utilising a focused ion‐beam implantation method capable of sub‐100 nm precision. The implanted regions exhibit telecom‐band emission, with a reduction in photoluminescence intensity and lifetime below 50 K, consistent with pyroelectric‐field effects in the host ...
Daniel Blight, Mason Adshead, Alessandro Prencipe, Maryam Sanaee, Katia Gallo, Richard J Curry   +5 more
wiley   +1 more source

Towards a Framework for Covert Communications for Mitigating Traffic Detection Attacks

Computers
This article addresses a critical security challenge in Internet of Things (IoT) systems, which are vulnerable to traffic detection attacks due to their reliance on shared wireless communication channels.
Abdallah Farraj
doaj   +1 more source

Improving the Robustness of Visual Teach‐and‐Repeat Navigation Using Drift Error Correction and Event‐Based Vision for Low‐Light Environments

Advanced Robotics Research, EarlyView.
Visual teach‐and‐repeat (VTR) navigation allows robots to learn and follow routes without building a full metric map. We show that navigation accuracy for VTR can be improved by integrating a topological map with error‐drift correction based on stereo vision.
Fuhai Ling, Ze Huang, Tony J. Prescott
wiley   +1 more source