Results 41 to 50 of about 7,340 (215)

Optoelectronically Active GaAs/GeSn‐MQW/Ge Heterojunctions Created via Semiconductor Grafting

Advanced Optical Materials, EarlyView.
Semiconductor Grafting enables a lattice‐mismatched GaAs/GeSn‐MQW/Ge heterojunction with engineered band offsets and optical field distribution. The enlarged conduction and valence band discontinuities govern asymmetric carrier transport, producing bias‐dependent dual‐mode photodetection from visible to near‐infrared wavelengths.
Jie Zhou, Haibo Wang, Yang Liu, Yifu Guo, Alireza Abrand, Yiran Li, Jiarui Gong, Hieu D. Trinh, Po Rei Huang, Jianping Shen, Shengqiang Xu, Daniel Vincent, Samuel Haessly, Yi Lu, Munho Kim, Shui‐Qing Yu, Parsian K. Mohseni, Guo‐En Chang, Zetian Mi, Kai Sun, Xiao Gong, Mikhail A. Kats, Zhenqiang Ma   +22 more
wiley   +1 more source

Chameleonic Color‐Variable Microbead Emitters for Multilevel Spectroscopic Encryption from Visible to Infrared Wavelengths

Advanced Optical Materials, EarlyView.
Whispering‐gallery‐mode microresonators with sharp resonant peaks enable photonic barcoding. Similar to a chameleon, a rare‐earth‐free microcavity with π‐conjugated PAHs enables visibleto‐near infrared color generation from a single microbead. The unique resonat emission (spectral barcode) can be dynamically transformed via excitation wavelength change,
Barun Kumar Barman, Keisuke Watanabe, Kenzo Deguchi, Shinobu Ohki, Kenjiro Hashi, Atsushi Goto, Tadaaki Nagao   +6 more
wiley   +1 more source

A hybrid method combining the Time-Domain Method of Moments, the Time-Domain Uniform Theory of Diffraction and the FDTD [PDF]

Advances in Radio Science, 2007
In this paper a hybrid method combining the Time-Domain Method of Moments (TD-MoM), the Time-Domain Uniform Theory of Diffraction (TD-UTD) and the Finite-Difference Time-Domain Method (FDTD) is presented.
A. Becker, V. Hansen
doaj  

Multi‐Dielectric Metasurfaces for Ultrabright, Tunable Structural Color and Reconfigurable Optical Filtering with Extraordinarily Large Color Span

Advanced Optical Materials, EarlyView.
Structural color generation is an emerging field for digital display and printing applications. This report presents a novel truncated‐cone design and the first use of GaP sandwiched between two layers of TiO2, demonstrating ultra‐bright, tunable colors with a record color gamut.
Md Rumon Miah, Yavuz Selim Aydın, Hilmi Volkan Demir   +2 more
wiley   +1 more source

CLEAN Technique to Classify and Detect Objects in Subsurface Imaging

International Journal of Antennas and Propagation, 2012
An image domain CLEAN technique, for nondestructive and noncontacting subsurface imaging, is discussed. Recently introduced finite-difference time-domain- (FDTD-) based virtual tool, GrGPR, is used to create imaging scenarios and to generate synthetic ...
E. Karpat
doaj   +1 more source

Photon‐Sphere Modes in Curved Optical Microcavities: A Black‐Hole Analogue Laser

Advanced Science, EarlyView.
An optical analogue of a Schwarzschild black hole is realized using curved microcavities that preserve light‐like geodesics. A new family of laser modes confined around the photon sphere is identified alongside conventional whispering‐gallery modes. Analytical theory, numerical simulations, and experiments reveal curvature‐induced confinement, enabling
Chenni Xu, Aswathy Sundaresan, Nazire‐Begüm Kazkal, Clement Lafargue, Lior Zarfaty, Li‐Gang Wang, Ofek Birnholtz, Dominique Decanini, Melanie Lebental, Patrick Sebbah   +9 more
wiley   +1 more source

Photonic Time Crystals and Time‐Varying Electromagnetic Metamatter: A New Direction for Ultrafast Tunable Photonic and Microwave Materials and Devices

Advanced Science, EarlyView.
Photonic time crystals (PTCs) are systems in which electromagnetic parameters are modulated periodically in time, producing momentum bandgaps via temporal scattering rather than spatial Bragg processes. This review examines the theoretical frameworks, modeling, and computational tools for time‐varying media, and summarizes experimental demonstrations ...
Ranjan Kumar Patel, Shriram Ramanathan, Ronald P. Jenkins, Michael J. Carter   +3 more
wiley   +1 more source

New approach to far field analysis for radiation pattern estimation using FDTD method [PDF]

Serbian Journal of Electrical Engineering, 2014
In this paper an approach to efficient computation of radiation pattern in FDTD simulation environment is presented. A necessary large distance from the radiating object is achieved by multigrid space discretization with unilaterally connected ...
Nikolić Bojana, Dimitrijević Bojan, Aleksić Slavoljub, Raičević Nebojša, Milošević Nenad   +4 more
doaj   +1 more source

Reconfigurable, Temperature Resilient Phase‐Change Metasurfaces Fabricated via High Throughput Nanoimprinting Lithography

Advanced Science, EarlyView.
ABSTRACT The combination of metasurfaces with chalcogenide phase‐change materials is a highly promising route toward the development of multifunctional and reconfigurable nanophotonic devices. However, their transition into real‐world devices is hindered by several technological challenges. This includes, amongst others, the lack of large area photonic
Carlota de Ruiz de Galarreta, Yinghao Zhao, Jose Mendoza‐Carreño, José M. Caicedo, José Santiso, C. David Wright, M. Isabel Alonso, Jiafang Li, Agustin Mihi   +8 more
wiley   +1 more source

FDTD Analysis of Electromagnetic Wave Propagation in an Inhomogeneous Ionosphere under Arbitrary-Direction Geomagnetic Field [PDF]

Journal of the Korean Institute of Electromagnetic Engineering and Science, 2018
The finite-difference time-domain (FDTD) model was developed to analyze electromagnetic (EM) wave propagation in an inhomogeneous ionosphere. The EM analysis of ionosphere is complicated, owing to various propagation environments that are significantly ...
Jun-Ho Kweon, Min-Seok Park, Jeahoon Cho, Kyung-Young Jung   +3 more
doaj   +1 more source