Results 81 to 90 of about 2,288 (244)

Far‐Infrared Hyperbolic Phonon–Polaritons in Zirconium Disulfide

Advanced Materials, EarlyView.
An unpatterned ZrS2${\rm ZrS}_2$ flake, coupled to far‐field infrared light by metal nanoribbons, reveals hyperbolic phonon polaritons with multiple higher‐order branches and effective refractive indices up to 223. This resonator‐assisted approach establishes ZrS2${\rm ZrS}_2$ as a compact van der Waals platform for deeply subwavelength far‐infrared ...
Subhodip Saha, Ryan Kowalski, Joseph R. Matson, Thomas G. Folland, Tony Low, Joshua D. Caldwell, In‐Ho Lee, Sang‐Hyun Oh   +7 more
wiley   +1 more source

Electrically Coded Retinomorphic Spectrophotodetector

Advanced Materials, EarlyView.
Self‐powered retinomorphic pyro‐photodetector is demonstrated that avoids machine‐learning post‐processing and covers 365–940 nm. Electrostatic balancing of built‐in potential produces an electrical wavelength code, delivering <3 nm wavelength decoding accuracy with ∼46 µs response.
Mohit Kumar, Hyunmin Dang, Hyungtak Seo
wiley   +1 more source

Wideband spectrum sensing in unknown white Gaussian noise

IET Communications, 2008
The spectrum sensing of a wideband frequency range is studied by dividing it into multiple subbands. It is assumed that in each subband either a primary user (PU) is active or absent in a additive white Gaussian noise environment with an unknown variance. It is also assumed that at least a minimum given number of subbands are vacant of PUs.
Abbas Taherpour, Saeed Gazor, Masoumeh Nasiri-Kenari   +2 more
openaire   +1 more source

Unveiling α‐MoO3 as a High‐Index, Low‐Loss Anisotropic Material: Bridging the Gap From Mid‐Infrared to Ultraviolet Nanophotonics

Advanced Materials, EarlyView.
α‐MoO3 is established as a high‐index, low‐loss anisotropic platform bridging mid‐infrared polaritonics and ultraviolet‐visible nanophotonics. Spectroscopic ellipsometry and calculations reveal refractive indices exceeding 3.9, with the largest in‐plane birefringence among transparent layered crystals at 425–500 nm, enabling zero‐order UV waveplates ...
Adilet N. Toksumakov, Dmitriy V. Grudinin, Georgy A. Ermolaev, Alexey P. Tsapenko, Anton A. Minnekhanov, Konstantin V. Kravtsov, Nikolay V. Pak, Arslan B. Mazitov, Andrey A. Vyshnevyy, Aleksandr S. Slavich, Ivan A. Kruglov, Gleb I. Tselikov, Aleksey V. Arsenin, Kostya S. Novoselov, Valentyn S. Volkov   +14 more
wiley   +1 more source

Controlling Radiative Phonons in the van der Waals Ferroelectric NbOI2

Advanced Materials, EarlyView.
Using a simple mirror geometry, this work demonstrates local‐density‐of‐optical‐states control of THz phonon emission in van der Waals ferroelectric NbOI2. By engineering the photonic environment, the phonon Q‐factor, linewidth, peak frequency, and emission intensity are reversibly tuned by over an order of magnitude, revealing radiative phonons as ...
Baolong Zhang, Ruihuan Duan, Sobhan Subhra Mishra, Thomas Tan Caiwei, Zheng Liu, Ranjan Singh   +5 more
wiley   +1 more source

Electrochromic Adaptive Solar Heater and Sub‐Ambient Passive Daytime Radiative Cooler

Advanced Materials, EarlyView.
An electrochromic Cu–Bi nanocluster device dynamically switches between solar heating and daytime sub‐ambient radiative cooling without mechanical motion. Defect‐activated graphene, minimized electrolyte loss, and pulse‐assisted reversible electrodeposition enable opposite solar and mid‐infrared modulation in one opaque platform, establishing a design ...
Chenxi Sui, Qizhang Li, Yu Han, Xinyu Dou, Gangbin Yan, Jiadong Liu, Blake Harris, Jinlei Li, Alexander S. Filatov, Qingsong Fan, Ching‐Tai Fu, Po‐Chun Hsu   +11 more
wiley   +1 more source

A Sparsity Adaptive Algorithm for Wideband Compressive Spectrum Sensing

Dianxin kexue, 2014
Traditional spectrum sensing based on compressed sensing assumes that the sparsity is known, in fact,it is unknown and time-varying. To solve the problem, a sparsity adaptive algorithm for wideband spectrum sensing was proposed.
Zhijin Zhao, Junwei Hu
doaj   +2 more sources

Soft Skins With Reversible Thickness Morphing: Materials, Mechanisms, and Applications

Advanced Materials, EarlyView.
Evolution of electronic skin (e‐skin) technologies toward adaptive, multifunctional soft skins. Phase I highlights early rigid and discrete sensory interfaces. Phase II shows the transition toward flexible, stretchable, and large‐area e‐skin. Phase III captures the emergence of computational e‐skin.
Oliver Ozioko, Chiamaka Akah, Ravinder Dahiya   +2 more
wiley   +1 more source

Benchmarking Coaxial and Angular Optical Emission Spectroscopy With Recommendations for Reliable Compositional In Situ Monitoring During Laser Powder Bed Fusion

Advanced Materials Technologies, EarlyView.
ABSTRACT Real‐time insight into local chemistry is critical for reliable part quality in additive manufacturing, especially laser powder bed fusion (PBF‑LB/M), where rapid thermal cycles and localized evaporation can undermine part performance. Optical emission spectroscopy (OES) offers non‑intrusive, in situ plume monitoring, but detection geometry ...
Philipp Gabriel, Bastian Jülich, Anna Rosa Ziefuss, Florian Eibl, Stephan Barcikowski   +4 more
wiley   +1 more source

Selective Sensing and Access Strategy to Maximize Throughput in Cognitive Radio Sensor Network

International Journal of Distributed Sensor Networks, 2014
This paper presents a selective spectrum sensing and access strategy in a cognitive radio sensor network (CRSN), in order to maximize the throughput of secondary user (SU) system.
Weijun Li, Chao Yang, Zhenquan Wu, Beihai Tan, Yuli Fu   +4 more
doaj   +1 more source