Results 11 to 20 of about 1,379 (173)

Varifocal Meta-Lens for Multifunctional Focusing and Imaging. [PDF]

Adv Sci (Weinh)
A varifocal meta‐lens enables dynamic switching between conventional focusing and non‐diffracting autofocusing beams, relying on a phase design with dual interpretations in both real space and the spatial frequency domain. By integrating a Moiré‐based tuning mechanism, the system achieves continuous focal length control in both modes.
Lin R, Yao J, Chen C, Wu J, Zhou J, Wang Z, Tsai DP.   +6 more
europepmc   +2 more sources

Criteria for selecting the Paganin-filter reconstruction parameter in X-ray phase-contrast tomography. [PDF]

J Synchrotron Radiat
The development of a criterion for near‐optimal selection of the Paganin‐filter parameter based on noise power analysis measured via an image's noise power spectrum is described.The Paganin filter, widely employed in propagation‐based phase‐contrast X‐ray computed tomography with synchrotron light, attenuates phase effects and suppresses high‐frequency
Miqueles EX, de Oliveira EL, Carvalho M, Paganin DM.   +3 more
europepmc   +2 more sources

Abruptly autofocusing waves [PDF]

Optics Letters, 2010
We introduce a new class of (2+1)D spatial and (3+1)D spatiotemporal waves that tend to autofocus in an abrupt fashion. While the maximum intensity of such a radial wave remains almost constant during propagation, it suddenly increases by orders of magnitude right before its focal point.
Efremidis, Nikolaos K., Christodoulides, Demetrios N.   +1 more
openaire   +5 more sources

Water-Immersed GaP Huygens' Meta-Optics for Visible Structured Light Generation. [PDF]

Adv Sci (Weinh)
Ultrathin GaP Huygens’ metasurfaces operating in the visible regime generate structured light beams underwater, including focusing Gaussian beams, abruptly autofocusing beams, Bessel beams, and optical vortices. The platform offers enhanced fabrication tolerance and mechanical stability, establishing a robust route toward compact underwater ...
Lee JH, Wang HY, Ho PY, Chung YC, Duh RT, Chiang CC, Horng RH, Huang YW, Tseng ML.   +8 more
europepmc   +2 more sources

Changing the trajectory of Airy beam sets with spatial carriers

Компьютерная оптика, 2022
In this paper, we study a change in the propagation trajectory of a set of autofocusing laser beams using a fractional Fourier transform. Clusters of displaced bounded Airy-Gaussian beams supplemented by a phase function that deflects the beam similarly ...
A.O. Frolov, А.V. Ustinov, S.N. Khonina
doaj   +1 more source

Virtual Staining of Defocused Autofluorescence Images of Unlabeled Tissue Using Deep Neural Networks

Intelligent Computing, 2022
Deep learning-based virtual staining was developed to introduce image contrast to label-free tissue sections, digitally matching the histological staining, which is time-consuming, labor-intensive, and destructive to tissue.
Yijie Zhang, Luzhe Huang, Tairan Liu, Keyi Cheng, Kevin de Haan, Yuzhu Li, Bijie Bai, Aydogan Ozcan   +7 more
doaj   +1 more source

SPA-GAN: SAR Parametric Autofocusing Method with Generative Adversarial Network

Remote Sensing, 2022
Traditional synthetic aperture radar (SAR) autofocusing methods are based on the point-scattering model, which assumes the scattering phases of a target to be a constant.
Zegang Ding, Ziwen Wang, Yangkai Wei, Linghao Li, Xinnong Ma, Tianyi Zhang, Tao Zeng   +6 more
doaj   +1 more source

Generation and regulation of two-dimensional autofocusing Airy beams based on holographic metasurfaces

Journal of Information and Intelligence, 2023
This paper proposes a new method to generate a two-dimensional (2D) Airy beam and Airy autofocusing beam by using the scalar holographic metasurface with amplitude-phase modulation in the microwave band.
Song Zhang, Hao Xue, Yicen Li, Jiaqi Han, Haixia Liu, Long Li, Tie Jun Cui   +6 more
doaj   +1 more source

zPIE: an autofocusing algorithm for ptychography [PDF]

Optics Letters, 2020
An autofocusing algorithm for ptychography is proposed. The method optimizes a sharpness metric that would be observed in a differential interference microscope and is valid for both amplitude and phase modulating specimens. We experimentally demonstrate that the algorithm, based on the extended ptychographic iterative engine (ePIE), calibrates the ...
Loetgering, Lars, Du, Mengqi, Eikema, Kjeld S. E., Witte, Stefan   +3 more
openaire   +3 more sources

Safety and Efficacy of Magnetic Resonance-Guided Focused Ultrasound Surgery With Autofocusing Echo Imaging

Frontiers in Neuroscience, 2021
ObjectiveMagnetic resonance-guided focused ultrasound surgery (MRgFUS) lesioning is a new treatment for brain disorders. However, the skull is a major barrier of ultrasound sonication in MRgFUS because it has an irregular surface and varies its size and ...
Kyung Won Chang, Itay Rachmilevitch, Won Seok Chang, Hyun Ho Jung, Eyal Zadicario, Oleg Prus, Jin Woo Chang   +6 more
doaj   +1 more source