Results 41 to 50 of about 96,711 (321)

Digging Deeper through Biological Specimens Using Adaptive Optics-Based Optical Microscopy

open access: yesPhotonics, 2023
Optical microscopy is a vital tool for visualizing the cellular and sub-cellular structures of biological specimens. However, due to its limited penetration depth, its biological applicability has been hindered.
Gagan Raju, Nirmal Mazumder
doaj   +1 more source

Non-common Path Aberration Correction in an Adaptive Optics Scanning Ophthalmoscope [PDF]

open access: yes, 2014
The correction of non-common path aberrations (NCPAs) between the imaging and wavefront sensing channel in a confocal scanning adaptive optics ophthalmoscope is demonstrated.
Dubra, Alfredo, Sulai, Yusufu N.
core   +2 more sources

Beam wavefront retrieval by convoluted spatial spectral benchmark

open access: yesMatter and Radiation at Extremes, 2021
We propose a method for retrieving a beam wavefront from its near-field intensity distribution after a 4f system by simply inserting a benchmark at the Fourier plane.
Xuewei Deng   +5 more
doaj   +1 more source

Compressive Shack-Hartmann Wavefront Sensor based on Deep Neural Networks [PDF]

open access: yes, 2020
The Shack-Hartmann wavefront sensor is widely used to measure aberrations induced by atmospheric turbulence in adaptive optics systems. However if there exists strong atmospheric turbulence or the brightness of guide stars is low, the accuracy of wavefront measurements will be affected.
arxiv   +1 more source

Space-variant Shack-Hartmann wavefront sensing based on affine transformation estimation [PDF]

open access: yesApplied Optics, 2022, 2022
The space-variant wavefront reconstruction problem inherently exists in deep tissue imaging. In this paper,we propose a framework of Shack-Hartmann wavefront space-variant sensing with extended source illumination. The space-variant wavefront is modeled as a four-dimensional function where two dimensionsare in the spatial domain and two in the Fourier ...
arxiv   +1 more source

Single conjugate adaptive optics for the ELT instrument METIS [PDF]

open access: yes, 2018
The ELT is a 39m large, ground-based optical and near- to mid-infrared telescope under construction in the Chilean Atacama desert. Operation is planned to start around the middle of the next decade.
Absil, Olivier   +9 more
core   +3 more sources

Shack Hartmann wavefront sensor with array of phase coded masks [PDF]

open access: yes, 2021
Shack-Hartmann wavefront sensors (SHWS) are generally used to measure the wavefront curvature of light beams. Measurement accuracy and the sensitivity of these sensors are important factors for better wavefront sensing. In this study, we demonstrate a new type of SHWS with better measurement accuracy than the regular SHWS.
arxiv   +1 more source

Telescope to Observe Planetary Systems (TOPS): a high throughput 1.2-m visible telescope with a small inner working angle [PDF]

open access: yes, 2006
The Telescope to Observe Planetary Systems (TOPS) is a proposed space mission to image in the visible (0.4-0.9 micron) planetary systems of nearby stars simultaneously in 16 spectral bands (resolution R~20). For the ~10 most favorable stars, it will have
/   +22 more
core   +2 more sources

Joint optimization of wavefront sensing and reconstruction with automatic differentiation [PDF]

open access: yesarXiv, 2022
High-contrast imaging instruments need extreme wavefront control to directly image exoplanets. This requires highly sensitive wavefront sensors which optimally make use of the available photons to sense the wavefront. Here, we propose to numerically optimize Fourier-filtering wavefront sensors using automatic differentiation.
arxiv  

Wavefront sensing reveals optical coherence [PDF]

open access: yesNature Communications, 2014
Wavefront sensing is a set of techniques providing efficient means to ascertain the shape of an optical wavefront or its deviation from an ideal reference. Due to its wide dynamical range and high optical efficiency, the Shack-Hartmann is nowadays the most widely used of these sensors.
B. Stoklasa   +4 more
openaire   +4 more sources

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