Results 21 to 30 of about 2,554 (206)
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. +1 more
openaire +5 more sources
Robust autofocusing in microscopy [PDF]
Cytometry, 2000 A critical step in automatic microscopy is focusing. This report describes a robust and fast autofocus approach useful for a wide range of microscopic modalities and preparations.The focus curve is measured over the complete focal range, reducing the chance that the best focus position is determined by dust or optical artifacts.
Geusebroek, J.M. +3 more
openaire +6 more sources
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 +3 more
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Generation of Complex Transverse Energy Flow Distributions with Autofocusing Optical Vortex Beams
Micromachines, 2021 Optical vortex (OV) beams are widely used for the generation of light fields with transverse energy flow inducing orbital motion of the nano- and microparticles in the transverse plane.
Svetlana N. Khonina +3 more
doaj +1 more source
High-Resolution ISAR Imaging and Autofocusing via 2D-ADMM-Net
Remote Sensing, 2021 A deep-learning architecture, dubbed as the 2D-ADMM-Net (2D-ADN), is proposed in this article. It provides effective high-resolution 2D inverse synthetic aperture radar (ISAR) imaging under scenarios of low SNRs and incomplete data, by combining model ...
Xiaoyong Li, Xueru Bai, Feng Zhou
doaj +1 more source
Criteria for selecting the Paganin-filter reconstruction parameter in X-ray phase-contrast tomography. [PDF]
J Synchrotron RadiatThe 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 +3 more
europepmc +2 more sources
Autofocusing in optical scanning holography [PDF]
Applied Optics, 2009 We present autofocusing in optical scanning holography (OSH) with experimental results. We first record the complex hologram of an object using OSH and then create the Fresnel zone plate (FZP) that codes the object constant within the depth range of the object using Gaussian low-pass filtering.
Kim, Taegeun, Poon, Ting-Chung
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Frequency conversion of abruptly autofocusing waves
, 2021 Abruptly autofocusing waves and associated ring-Airy (RA) beams are attracting increasing interest owing to their fascinating properties such as their ability of abruptly autofocusing to small F-number.
Dong-Mei Wang (315160) +5 more
core +1 more source
Robust autofocusing propagation in turbulence
, 2023 We conducted a comprehensive study on the robust propagation of the same spot-size Gaussian beam (SSGB), same envelope Gaussian beam (SEGB), Circular Airy beam (CAB) and Circular Pearcey beam (CPB) in complex environments.
Liu, Nana +6 more
core +2 more sources
Autofocusing and Self-Healing Optical Vortices Realized via Circular Cubic Phase Modulation
Crystals, 2022 Optical vortices have drawn extensive research interests due to their widespread applications in various fields. Therefore, it is of great significance to modulate optical vortices to endow them with more properties.
Haozhe Xiong +6 more
doaj +1 more source