Results 71 to 80 of about 64,627 (124)

Wavefront reconstruction from tangential and sagittal curvature

Applied Optics, 2014
In a previous contribution [Appl. Opt.51, 8599 (2012)], a coauthor of this work presented a method for reconstructing the wavefront aberration from tangential refractive power data measured using dynamic skiascopy. Here we propose a new regularized least squares method where the wavefront is reconstructed not only using tangential but also sagittal ...
Canales, J., Barbero, Sergio, Portilla, Javier, López-Alonso, J.M.   +3 more
openaire   +4 more sources

Automatic Compressive Sensing of Shack–Hartmann Sensors Based on the Vision Transformer

Photonics
Shack–Hartmann wavefront sensors (SHWFSs) are crucial for detecting distortions in adaptive optics systems, but the accuracy of wavefront reconstruction is often hampered by low guide star brightness or strong atmospheric turbulence.
Qingyang Zhang, Heng Zuo, Xiangqun Cui, Xiangyan Yuan, Tianzhu Hu   +4 more
doaj   +1 more source

Quantitative phase imaging based on holography: trends and new perspectives

Light: Science & Applications
In 1948, Dennis Gabor proposed the concept of holography, providing a pioneering solution to a quantitative description of the optical wavefront.
Zhengzhong Huang, Liangcai Cao
doaj   +1 more source

Efficient wavefront sensing for space-based adaptive optics [PDF]

arXiv, 2019
Future large space telescopes will be equipped with adaptive optics (AO) to overcome wavefront aberrations and achieve high contrast for imaging faint astronomical objects, such as earth-like exoplanets and debris disks. In contrast to AO that is widely used in ground telescopes, space-based AO systems will use focal plane wavefront sensing to measure ...
arxiv  

A Review: Phase Measurement Techniques Based on Metasurfaces

Photonics
Phase carries crucial information about the light propagation process, and the visualization and quantitative measurement of phase have important applications, ranging from ultra-precision metrology to biomedical imaging.
Zhicheng Zhao, Yueqiang Hu, Shanyong Chen   +2 more
doaj   +1 more source

Sparse Reconstruction of Wavefronts using an Over-Complete Phase Dictionary [PDF]

arXiv
Wavefront reconstruction is a critical component in various optical systems, including adaptive optics, interferometry, and phase contrast imaging. Traditional reconstruction methods often employ either the Cartesian (pixel) basis or the Zernike polynomial basis. While the Cartesian basis is adept at capturing high-frequency features, it is susceptible
arxiv  

Large-Dynamic-Range Ocular Aberration Measurement Based on Deep Learning with a Shack–Hartmann Wavefront Sensor

Sensors
The Shack–Hartmann wavefront sensor (SHWFS) is widely utilized for ocular aberration measurement. However, large ocular aberrations caused by individual differences can easily make the spot move out of the range of the corresponding sub-aperture in SHWFS,
Haobo Zhang, Junlei Zhao, Hao Chen, Zitao Zhang, Chun Yin, Shengqian Wang   +5 more
doaj   +1 more source

Wavefront Estimation From a Single Measurement: Uniqueness and Algorithms [PDF]

arXiv
Wavefront estimation is an essential component of adaptive optics where the goal is to recover the underlying phase from its Fourier magnitude. While this may sound identical to classical phase retrieval, wavefront estimation faces more strict requirements regarding uniqueness as adaptive optics systems need a unique phase to compensate for the ...
arxiv  

Wavefront Reconstruction Using Two-Frame Random Interferometry Based on Swin-Unet

Photonics
Due to its high precision, phase-shifting interferometry (PSI) is a commonly used optical component detection method in interferometers. However, traditional PSI, which is susceptible to environmental factors, is costly, with piezoelectric ceramic ...
Xindong Shu, Baopeng Li, Zhen Ma
doaj   +1 more source

On Phase Unwrapping via Digital Wavefront Sensors [PDF]

arXiv
In this paper, we derive a new class of methods for the classic 2D phase unwrapping problem of recovering a phase function from its wrapped form. For this, we consider the wrapped phase as a wavefront aberration in an optical system, and use reconstruction methods for (digital) wavefront sensors for its recovery.
arxiv