Results 101 to 110 of about 239,453 (286)

Study on the Difference in Wavefront Distortion on Beams Caused by Wavelength Differences in the Strong Turbulence Region

Applied Sciences
In free-space optical communication, the transmission of signal light and beacon light of differing wavelengths through the same atmospheric channel encounters variations in how the atmospheric refractive index absorbs and scatters light.
Meimiao Han, Xizheng Ke, Jingyuan Liang
doaj   +1 more source

SDF‐Guided Point Cloud Generation Framework for Mesh‐Free CFD

International Journal for Numerical Methods in Fluids, EarlyView.
This paper presents different methods for generating clouds of points around objects for use with meshless methods in computational fluid dynamics. This image shows the cloud generated around the original ROBIN body. ABSTRACT Meshing is a bottleneck of CFD workflows, especially when complex geometries are considered.
Tao Zhang, George N. Barakos
wiley   +1 more source

Multiplexed wavefront sensing with a thin diffuser [PDF]

arXiv, 2023
In astronomy or biological imaging, refractive index inhomogeneities of e.g. atmosphere or tissues induce optical aberrations which degrade the desired information hidden behind the medium. A standard approach consists in measuring these aberrations with a wavefront sensor (e.g Shack-Hartmann) located in the pupil plane, and compensating them either ...
arxiv  

Deformable Membrane Mirror for Wavefront Correction

Defence Science Journal, 2009
Deformable or adaptive mirrors are used in modern adaptive optics systems for direct correction of the aberrations in the light wavefront. Conventional deformable mirrors used for this purpose are expensive electromechanical devices. Deformable membrane mirror fabricated using microelectromechanical systems (MEMS) technology is a low cost, compact ...
A. K. Meena, Amita Gupta, Ranvir Singh, Monika Chaudhary, Shailesh Kumar, V. K. Sarvanan   +5 more
openaire   +2 more sources

High-contrast imaging in polychromatic light with the self-coherent camera

, 2014
Context. In the context of direct imaging of exoplanets, coronagraphs are commonly proposed to reach the required very high contrast levels. However, wavefront aberrations induce speckles in their focal plane and limit their performance. Aims.
Baudoz, Pierre, Galicher, Raphaël, Mazoyer, Johan, Rousset, Gérard   +3 more
core   +2 more sources

Microsaccades Tracking by Secondary Speckle Pattern Analysis

Journal of Biophotonics, EarlyView.
A new approach for detecting microsaccades is introduced using secondary speckle patterns reflected from the sclera. This method offers potential benefits in capturing subtle eye movements and overcoming limitations in traditional pupil‐tracking systems.
Ola Shteinberg, Sergey Agdarov, Yafim Beiderman, Yoram S. Bonneh, Inbal Ziv, Zeev Kalyuzhner, Zeev Zalevsky   +6 more
wiley   +1 more source

Sensing Dog Brain Reactions to Smell by AI Speckle Pattern Analysis

Journal of Biophotonics, EarlyView.
The setup of our experiment is shown on Labrador, Johny, a canine participant of our research. The schematic of the setup features: green laser, digital camera, source of smell, and computer. Regions of the brain that were tested are highlighted. Note that the hippocampus and amygdala are on both sides of the dog's brain.
Ilana Propp, Marianna Beiderman, Sergey Agdarov, Yafim Beiderman, Maxi Blum, Zeev Zalevsky   +5 more
wiley   +1 more source

Real-time Adaptive Optics with pyramid wavefront sensors: Accurate wavefront reconstruction using iterative methods

, 2018
In this paper, we address the inverse problem of fast, stable, and high-quality wavefront reconstruction from pyramid wavefront sensor data for Adaptive Optics systems on Extremely Large Telescopes.
Hutterer, Victoria, Ramlau, Ronny, Shatokhina, Iuliia   +2 more
core   +1 more source

Depth‐enhanced light field camera system based on focus‐tunable geometric phase lens module

Journal of the Society for Information Display, EarlyView.
We propose a GPL‐based LF camera that significantly extends the depth range over passive optics. During elemental image acquisition and LF rendering, chromatic aberration is compensated by adjusting reconstruction depth and magnification per color channel, with optimized GPL operations considering color‐dependent depth of focus.
Hyeon‐Su Jeong, Munkh‐Uchral Erdenebat, Jin‐Hyeok Seo, Min‐Seok Kim, Young‐Min Cho, Jae‐Won Lee, Tae‐Hyun Lee, Kyung‐Il Joo, Hak‐Rin Kim   +8 more
wiley   +1 more source

Wavefront Phase Retrieval with Non-linear Curvature Sensors [PDF]

, 2012
Increasing interest in astronomical applications of non-linear curvature wavefront sensors for turbulence detection and correction makes it important to understand how best to handle the data they produce, particularly at low light levels. Algorithms for wavefront phase-retrieval from a four-plane curvature wavefront sensor are developed and compared ...
arxiv   +1 more source