Results 41 to 50 of about 48,988 (289)

A smooth introduction to the wavefront set

open access: yes, 2014
The wavefront set provides a precise description of the singularities of a distribution. Because of its ability to control the product of distributions, the wavefront set was a key element of recent progress in renormalized quantum field theory in curved
Alinhac S   +40 more
core   +3 more sources

Laser Guide Star for Large Segmented-Aperture Space Telescopes, Part I: Implications for Terrestrial Exoplanet Detection and Observatory Stability

open access: yes, 2018
Precision wavefront control on future segmented-aperture space telescopes presents significant challenges, particularly in the context of high-contrast exoplanet direct imaging.
Cahoy, Kerri L.   +6 more
core   +1 more source

A Tip–Tilt and Piston Detection Approach for Segmented Telescopes

open access: yesPhotonics, 2020
Accurate segmented mirror wavefront sensing and control is essential for next-generation large aperture telescope system design. In this paper, a direct tip–tilt and piston error detection technique based on model-based phase retrieval with multiple ...
Shun Qin, Wai Kin Chan
doaj   +1 more source

Modern approaches to cataract surgery with high visual acuity based on wavefront analysis

open access: yesОфтальмохирургия, 2023
Relevance. Until recently, visual acuity was the main criterion for determining the timing of surgery, but already in the early stages of cataract development, patients may suffer from reduced image quality, which affects the quality of life (“night ...
O.V. Shilovskikh   +3 more
doaj   +1 more source

Light-controllable metasurface for microwave wavefront manipulation

open access: yesOptics Express, 2020
Applying multiple physical fields to artificial manipulate electromagnetic waves is a highly stirring research. In this paper, we creatively combine light control with microwave scattering, realizing an optically coding metasurface for beam deflection based on anomalous reflection.
Lei Chen   +5 more
openaire   +2 more sources

Wavefront sensing with a brightest pixel selection algorithm

open access: yes, 2011
Astronomical adaptive optics systems with open-loop deformable mirror control have recently come on-line. In these systems, the deformable mirror surface is not included in the wavefront sensor paths, and so changes made to the deformable mirror are not ...
A. G. Basden   +16 more
core   +2 more sources

Coronagraphic Low Order Wavefront Sensor: Principle and Application to a Phase-Induced Amplitude Coronagraph [PDF]

open access: yes, 2009
High contrast coronagraphic imaging of the immediate surrounding of stars requires exquisite control of low-order wavefront aberrations, such as tip-tilt (pointing) and focus.
Belikov   +12 more
core   +1 more source

An All‐Optical Driven Bio‐Photovoltaic Interface for Active Control of Live Cells

open access: yesAdvanced Functional Materials, EarlyView.
Bio‐photovoltaic Interface (BIO‐PV‐I) for live cell manipulation is presented. BIO‐PV‐I can be activated non‐invasively and remotely to control the spatial motility, adhesion, and morphology of cells adhering to it. BIO‐PV‐I uses a patterned light‐induced electric potential in iron‐doped lithium niobate crystals whose light‐driven and reversible nature,
Lisa Miccio   +8 more
wiley   +1 more source

Model-based wavefront control for CCAT [PDF]

open access: yesSPIE Proceedings, 2011
The 25-m aperture CCAT submillimeter-wave telescope will have a primary mirror that is divided into 162 individual segments, each of which is provided with 3 positioning actuators. CCAT will be equipped with innovative Imaging Displacement Sensors (IDS) - inexpensive optical edge sensors - capable of accurately measuring all segment relative motions.
Redding, David   +5 more
openaire   +2 more sources

Measurement of Thermo-Elastic Deformation of an Optic using a Polarization Based Shearing Interferometer

open access: yes, 2012
A shearing interferometer is presented which uses polarization control to shear the wavefront and to modulate the interference pattern. The shear is generated by spatial walk-off in a birefringent crystal. By adjusting the orientation of the birefringent
Abramowitz   +14 more
core   +1 more source

Home - About - Disclaimer - Privacy