Results 31 to 40 of about 5,580 (232)
Nonparaxial accelerating Bessel-like beams [PDF]
, 2013 A new class of nonparaxial accelerating optical waves is introduced. These are beams with a Bessel-like profile that are capable of shifting laterally along fairly arbitrary trajectories as the wave propagates in free space.
Chremmos, Ioannis +1 more
core +3 more sources
Properties of off-axis caustics of autofocusing chirp beams
Компьютерная оптика, 2020 Autofocusing properties of chirp beams with an arbitrary power-law dependence on the radius are studied theoretically and numerically. Two- and three-parameter chirp beams are considered, the parameter variations of which make it possible to effectively ...
A.V. Ustinov, S.N. Khonina
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
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
IEEE Access, 2019 The spaceborne synthetic aperture radar (SAR) system working at P-band, is vulnerable to the ionospheric effect. The ionospheric scintillation will introduce random phase fluctuations into the SAR signal and deteriorate the imaging performance.
Lei Yu +4 more
doaj +1 more source
Autofocus for digital Fresnel holograms by use of a Fresnelet-sparsity criterion [PDF]
, 2004 We propose a robust autofocus method for reconstructing digital Fresnel holograms. The numerical reconstruction involves simulating the propagation of a complex wave front to the appropriate distance.
Liebling, Michael, Unser, Michael
core +2 more sources
Design and control of laser micromachining workstation [PDF]
, 2012 The production process of miniature devices and microsystems requires the utilization of non-conventional micromachining techniques. In the past few decades laser micromachining has became micro-manufacturing technique of choice for many industrial and ...
Baran, Eray Abdurrahman +6 more
core +1 more source
Graphics processing unit (GPU) aided wavefront-based autofocusing in microscopy
AIP Advances, 2018 Based on the wavefront sensing and propagation, the wavefront-based autofocus approach is proposed for potentially adopted in rapid autofocusing since it can precisely locate the focal plane but only requiring much fewer multi-focal image captures ...
Zhilong Jiang +4 more
doaj +1 more source
Abruptly autofocusing vortex beams
Optics Express, 2012 We generate abruptly autofocusing beams that produce vortices at the focus. We give explicit equations for the phase-only Fourier masks that generate these beams including explanations for controlling the focal distance and numerical aperture. We show experimental results for the focal distance, the vortex pattern and show that the diameter of the ...
Jeffrey A, Davis +2 more
openaire +2 more sources
A New Autofocusing Method Based on Brightness and Contrast for Color Cameras
Advances in Electrical and Computer Engineering, 2016 The autofocusing is one of the most important features of imaging devices. This feature directly affects the quality of the image taken by the imaging device. Currently, many studies are being performed to improve the feature of autofocusing.
SELEK, M.
doaj +1 more source