Results 61 to 70 of about 65,352 (331)
Generating Artificial Reference Images for Open Loop Correlation Wavefront Sensors [PDF]
, 2018 Shack-Hartmann wavefront sensors for both solar and laser guide star adaptive optics (with elongated spots) need to observe extended objects. Correlation techniques have been successfully employed to measure the wavefront gradient in solar adaptive optics systems and have been proposed for laser guide star systems.
arxiv +1 more source
Optical wavefront phase-tilt measurement using Si-photonic waveguide grating couplers [PDF]
arXiv, 2023 Silicon photonic wavefront phase-tilt sensors for wavefront monitoring using surface coupling grating arrays are demonstrated. The first design employs the intrinsic angle dependence of the grating coupling efficiency to determine local wavefront tilt, with a measured sensitivity of 7 dB/degree.
arxiv
Photonics, 2023 Atmospheric turbulence causes refractive index fluctuations, which in turn introduce extra distortions to the wavefront of the propagated radiation. It ultimately degrades telescope resolution (in imaging applications) and reduces radiation power density
Ilya Galaktionov +4 more
doaj +1 more source
Rebuilding ships while at sea—Character individuality, homology, and evolutionary innovation
Journal of Morphology, Volume 284, Issue 1, January 2023., 2023 Building on a previous account of evolutionary innovation, I propose here that evolutionary novelties are those individualized characters that are not homologous to any characters in the ancestor. Integrating functional and structural perspectives, I argue that functional as well as structural considerations are important for character ...
Gerhard Schlosser
wiley +1 more source
Experimental Trials With The Optical Differentiation Wavefront Sensor For Extended Objects [PDF]
arXiv, 2022 Commonly used wavefront sensors, the Shack Hartmann wavefront sensor and the pyramid wavefront sensor, for example, have large dynamic range or high sensitivity, trading one regime for the other. A new type of wavefront sensor is being developed and is currently undergoing testing at the University of Arizona's Center for Astronomical Adaptive Optics ...
arxiv
Compressive Shack-Hartmann Wavefront Sensor based on Deep Neural Networks [PDF]
, 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
An Optical Wavefront Sensor Based on a Double Layer Microlens Array
Sensors, 2011 In order to determine light aberrations, Shack-Hartmann optical wavefront sensors make use of microlens arrays (MLA) to divide the incident light into small parts and focus them onto image planes.
Hsiang-Chun Wei +3 more
doaj +1 more source
Wavefront Reconstruction of Shack-Hartmann with Under-Sampling of Sub-Apertures
Photonics, 2023 Shack-Hartmann wavefront sensor plays a key role in adaptive optics (AO) systems, which detect the aberrant wavefront by an array of micro-lenslets across the aperture pupil.
Jian Huang +3 more
doaj +1 more source
High Sensitivity Wavefront Sensing with a non-linear Curvature Wavefront Sensor [PDF]
, 2009 A new wavefront sensing approach, derived from the successful curvature wavefront sensing concept but using a non-linear phase retrieval wavefront reconstruction scheme, is described. The non-linear curvature wavefront sensor (nlCWFS) approaches the theoretical sensitivity limit imposed by fundamental physics by taking full advantage of wavefront ...
arxiv +1 more source
Wavefront sensing with a brightest pixel selection algorithm
, 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