Results 161 to 170 of about 13,728 (209)

Wavefront and Polarization Control with Metasurfaces

Imaging and Applied Optics 2015, 2015
Optically/electrically-thin metasurfaces that can steer, focus, and manipulate the polarization of transmitted electromagnetic waves are developed using systematic design procedures and planar fabrication processes.
Carl Pfeiffer, Anthony Grbic
openaire   +1 more source

Programmable Wavefront Control with Photopolymers

Controlling Light with Light: Photorefractive Effects, Photosensitivity, Fiber Gratings, Photonic Materials and More, 2007
By controlling the photocuring of polymer systems between optical substrates it is possible to accurately program a wide variety of wavefront patterns. Two distinct methods are described, and examples of programmed wavefront elements are presented.
Lawrence Sverdrup, Jeff Chomyn, Gomaa Abdelsadek, Jagdish Jethmalani, Andreas Dreher   +4 more
openaire   +1 more source

Modal wavefront control system

Conference on Laser and Electrooptical Systems, 1976
A 9-channel 100-Hz closed-loop modal multidither COAT (Coherent Optical Adaptive Technique) system is described that could be used to improve propagation of a laser beam through the atmosphere and compensate for system induced optical aberrations.
C. Neufeld, E. L. Sloan, M. L. Skolnick
openaire   +1 more source

Computer-controlled wavefront corrector

Soviet Journal of Quantum Electronics, 1989
It is shown that an optically controlled liquid-crystal spatial modulator can be used to form a given wavefront when focusing on a line or a plane. Focusing to form a line, a circle, and a square are demonstrated.
A A Vasil'ev, M A Vorontsov, A V Koryabin, A F Naumov, V I Shmal'gauzen   +4 more
openaire   +1 more source

Optimal wavefront control for adaptive segmented mirrors

Applied Optics, 1989
A ground-based astronomical telescope with a segmented primary mirror will suffer image-degrading wavefront aberrations from at least two sources: (1) atmospheric turbulence and (2) segment misalignment or figure errors of the mirror itself. This paper describes the derivation of a mirror control feedback matrix that assumes the presence of both types ...
J D, Downie, J W, Goodman
openaire   +2 more sources

Modeling of Wavefront Control Systems

2011
In Sect. 5.5, we introduced typical components of telescope wavefront control systems and explained their operation principles. We noted that wavefront control systems include wavefront sensors to measure optical quality, controllers that determine which control action to take, and actuation systems that adjust form or position of optical elements.We ...
Torben Andersen, Anita Enmark
openaire   +1 more source

Wavelet-based wavefront control

SPIE Proceedings, 2004
The objective of Adaptive Optics is to achieve dynamic correction of severely abberated systems. This effort will develop a novel adaptive optics approach based on wavelets. Distortions are imprinted on the wavefront in the form of a spatially varying phase field. A wavelet-based method is being developed to subtract out distortions to yield a fully
openaire   +1 more source

Optimal modal Fourier-transform wavefront control

Journal of the Optical Society of America A, 2005
Optimal modal Fourier-transform wavefront control combines the speed of Fourier-transform reconstruction (FTR) with real-time optimization of modal gains to form a fast, adaptive wavefront control scheme. Our modal basis is the real Fourier basis, which allows direct control of specific regions of the point-spread function.
Poyneer, Lisa, Véran, Jean-Pierre
openaire   +3 more sources

Plasmonic metamaterials for optical wavefront control

Frontiers in Optics 2011/Laser Science XXVII, 2011
We discuss progress in the development of devices containing arrays of resonant apertures utilizing phase shifts accompanying resonance. We show that lenses producing three-dimensional focussing and planar quarter-wave plates can be created.
A. Roberts, L. Lin, X.M. Goh
openaire   +1 more source

Wavefront Reconstruction and Control Systems

1998
Abstract The control system is the vital link between the wave front sensor and the wavefront corrector in all adaptive optics systems. Its function is to convert the wavefront measurements made by the sensor into a set of commands that are applied to the wavefront corrector to satisfy a suitable performance criterion, such as minimizing
openaire   +1 more source