Results 31 to 40 of about 6,059 (275)
Centroid-Predicted Deep Neural Network in Shack-Hartmann Sensors
IEEE Photonics Journal, 2022 The Shack-Hartmann wavefront sensor produces incorrect wavefront measurements when some sub-spots are weak and missing. In this paper, a method is proposed to predict the centroids of these sub-spots for the Shack-Hartmann wavefront sensor based on the ...
Mengmeng Zhao +6 more
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Linearity of the pyramid wavefront sensor
Optics Express, 2006 The pyramid wavefront sensor is very similar to the Fourier knife-edge test, but employs dynamic modulation to quantify the phase derivative. For circular modulation, we compare approximate geometrical optics calculations, more exact diffraction calculations, and experimental results.
Christopher Dainty +3 more
openaire +3 more sources
IEEE Photonics Journal, 2016 We describe a sequential operation approach for a three-sided pyramid wavefront sensor (PWFS) based on a micromirror array with hexagonal geometry. The geometrical optics analysis and numerical simulations show that a linear relationship exists between ...
Lu Chen +6 more
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Компьютерная оптика, 2021 The use of a multichannel wavefront sensor matched with phase Zernike functions to determine the type and magnitude of aberration in the analyzed wavefront is investigated.
P.A. Khorin +2 more
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Hartmann wavefront sensors and their application at FLASH [PDF]
Journal of Synchrotron Radiation, 2016 Different types of Hartmann wavefront sensors are presented which are usable for a variety of applications in the soft X-ray spectral region at FLASH, the free-electron laser (FEL) in Hamburg. As a typical application, online measurements of photon beam parameters during mirror alignment are reported on.
Keitel, Barbara +7 more
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Measuring Ocular Aberrations Sequentially Using a Digital Micromirror Device
Micromachines, 2019 The Hartmann⁻Shack wavefront sensor is widely used to measure aberrations in both astronomy and ophthalmology. Yet, the dynamic range of the sensor is limited by cross-talk between adjacent lenslets.
Alessandra Carmichael Martins +1 more
doaj +1 more source
A Local Threshold Checkerboard Algorithm for Adaptive Optics System With a Plenoptic Sensor
IEEE Photonics Journal, 2022 Adaptive optics systems will encounter challenges under strong atmospheric turbulence conditions. Recently, a modified approach based on plenoptic sensor has attracted considerable attention.
Zhichong Wang +5 more
doaj +1 more source
Alternative pyramid wavefront sensors [PDF]
Journal of Astronomical Telescopes, Instruments, and Systems, 2017 The feasibility of a lenslet-based pyramid wavefront sensor (L-PWFS) and a double roof prism-based PWFS (DR-PWFS) as alternatives to a classical PWFS are investigated in this work. Traditional PWFSs require shallow angles and strict apex tolerances, making them difficult to manufacture. Lenslet arrays and roof prisms, on the other hand, are both common
Kooten, M.A.M. van. +2 more
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Shack-Hartmann Wavefront Sensing of Ultrashort Optical Vortices
Sensors, 2021 Light beams carrying Orbital Angular Momentum (OAM), also known as optical vortices (OV), have led to fascinating new developments in fields ranging from quantum communication to novel light–matter interaction aspects. Even though several techniques have
Alok Kumar Pandey +4 more
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Wavefront sensors for adaptive optical systems [PDF]
Measurement Science Review, 2008 Possibilities of constructing a wavefront sensor for the adaptive system in the Big Solar Vacuum Telescope are considered. A modified correlation tracker (MCT) is proposed. The sensor is tested by measuring the displacement of the image of the solar granulation pattern in the first and second foci of the telescope under clear vision conditions.
O. N. Emaleev +4 more
openaire +4 more sources