Results 1 to 10 of about 4,513 (162)
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
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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
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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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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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Nonparaxial abruptly autofocusing beams [PDF]
Optics Letters, 2016 5 pages, 8 figures.
Raluca-Sorina Penciu +2 more
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Passive Autofocusing System for a Thermal Camera [PDF]
IEEE Access, 2020 La mayoría de las cámaras térmicas (infrarrojas) de hoy en día están equipadas con una lente motorizada para enfocar una escena manualmente. La naturaleza subjetiva del enfoque manual lo convierte en un proceso ineficiente y engorroso. Por el contrario, el enfoque automático (AF) obtiene la mejor imagen enfocada en función de una medida cuantitativa ...
Ali Rashid +6 more
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Band-specific phase engineering for curving and focusing light in waveguide arrays [PDF]
, 2012 Band specific design of curved light caustics and focusing in optical waveguide arrays is introduced. Going beyond the discrete, tight-binding model, which we examined recently, we show how the exact band structure and the associated diffraction ...
Chremmos, Ioannis +1 more
core +1 more source
Linear and nonlinear waves in surface and wedge index potentials [PDF]
, 2012 We study optical beams that are supported at the surface of a medium with a linear index potential and by a piecewise linear wedge type potential. In the linear limit the modes are described by Airy functions.
Efremidis, Nikolaos K. +2 more
core +1 more source
Caustic design in periodic lattices [PDF]
, 2012 We study curved trajectory dynamics and design in discrete array settings. We find that beams with power law phases produce curved caustics associated with the fold and cusp type catastrophes.
Chremmos, Ioannis +1 more
core +2 more sources
Polarimetric ISAR autofocusing
IET Signal Processing, 2008 Interest in polarimetric inverse synthetic aperture radar (ISAR) systems has been growing because of their capability to provide extra information about the imaged target compared with single polarisation ISAR systems. Target classification and recognition can be improved by exploiting full polarisation ISAR images.
MARTORELLA, MARCO +4 more
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