Results 1 to 10 of about 5,543,577 (334)

A singularity-free space-time [PDF]

Physical Review D, 1992
We show that the solution published in Ref.1 is geodesically complete and singularity-free. We also prove that the solution satisfies the stronger energy and causality conditions, such as global hyperbolicity, causal symmetry and causal stability.
Chinea, F. J., Fernandez-Jambrina, L., Senovilla, J. M. M.   +2 more
core   +9 more sources

Free-space high-Q nanophotonics [PDF]

Light: Science & Applications
High-Q nanophotonic devices hold great importance in both fundamental research and engineering applications. Their ability to provide high spectral resolution and enhanced light-matter interactions makes them promising in various fields such as sensing ...
Jianbo Yu, Wenzhe Yao, Min Qiu, Qiang Li
doaj   +2 more sources

Free-space optical spiking neural network [PDF]

PLoS ONE
Neuromorphic engineering has emerged as a promising avenue for developing brain-inspired computational systems. However, conventional electronic AI-based processors often encounter challenges related to processing speed and thermal dissipation.
Reyhane Ahmadi, Amirreza Ahmadnejad, Somayyeh Koohi   +2 more
doaj   +3 more sources

Optical vortex-antivortex crystallization in free space [PDF]

Nature Communications
Stable vortex lattices are basic dynamical patterns which have been demonstrated in physical systems including superconductor physics, Bose-Einstein condensates, hydrodynamics and optics. Vortex-antivortex (VAV) ensembles can be produced, self-organizing
Haolin Lin, Yixuan Liao, Guohua Liu, Jianbin Ren, Zhen Li, Zhenqiang Chen, Boris A. Malomed, Shenhe Fu   +7 more
doaj   +2 more sources

Diffractive optical computing in free space [PDF]

Nature Communications
Structured optical materials create new computing paradigms using photons, with transformative impact on various fields, including machine learning, computer vision, imaging, telecommunications, and sensing.
Jingtian Hu, Deniz Mengu, Dimitrios C. Tzarouchis, Brian Edwards, Nader Engheta, Aydogan Ozcan   +5 more
doaj   +2 more sources

Nonparaxial Propagation of Bessel Correlated Vortex Beams in Free Space. [PDF]

Micromachines (Basel), 2022
Petrov NI.
europepmc   +3 more sources

Revolutionizing Free-Space Optics: A Survey of Enabling Technologies, Challenges, Trends, and Prospects of Beyond 5G Free-Space Optical (FSO) Communication Systems. [PDF]

Sensors (Basel)
Alimi IA, Monteiro PP.
europepmc   +3 more sources

A Compact Double-Ridged Horn Antenna for Ultra-Wide Band Microwave Imaging

IEEE Open Journal of Antennas and Propagation, 2021
In this paper, we introduce a novel and compact double-ridged horn (DRH) antenna for ultra-wide band microwave imaging. We first develop theoretical considerations useful to derive effective design guidelines and, thus, realizing the antenna model ...
Stefania Diana, Danilo Brizi, Chiara Ciampalini, Guido Nenna, Agostino Monorchio   +4 more
doaj   +1 more source

X-ray, multispectral and chlorophyll fluorescence images: innovative methods for evaluating the physiological potential of rice seeds

Journal of Seed Science, 2023
: Image analysis techniques are expanding in agriculture and, for being fast, simple, and not destroying samples, they are interesting alternatives in the detection of immature rice seeds.
Artur Sousa Silva, Silvio Moure Cicero, Fabiano França da Silva, Francisco Guilhien Gomes-Junior   +3 more
doaj   +1 more source

Angle-Dependent Transport Theory-Based Ray Transfer Function for Non-Contact Diffuse Optical Tomographic Imaging

Photonics, 2023
This work presents a generalized angle-dependent ray transfer function that can accurately map the angular and spatial distribution of light intensities on the tissue surface onto a camera image plane in a non-contact camera-based imaging system.
Stephen Hyunkeol Kim, Jingfei Jia, Andreas H. Hielscher   +2 more
doaj   +1 more source