Results 181 to 190 of about 5,696 (229)

Wavefront correction based on a reflective liquid crystal wavefront sensor

Journal of Optics A: Pure and Applied Optics, 2008
A novel wavefront sensor (WFS) based on liquid crystal on silicon (LCOS) is demonstrated. The design of the liquid crystal microlens array with LCOS is given in detail. To save the energy of the incident light, an optimized optical design of the WFS is also considered.
L Hu, L Xuan, D Li, Z Cao, Q Mu, Y Liu, Z Peng, X Lu   +7 more
openaire   +1 more source

High-speed Holographic Wavefront Correction

Imaging and Applied Optics 2016, 2016
We present details of a compact, holographic adaptive optics system with 64 actuators and 100kHz bandwidth, but no computer. We are currently modifying our system with a view towards an on-sky test in a large astronomical telescope in late-2016.
openaire   +1 more source

Aperture size effect on ultrasonic wavefront distortion correction

IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control, 2004
The influences of aperture size on wavefront distortion correction are investigated both theoretically and numerically. A multilayer, phase-screen model is assumed to be the underlying, distorting medium. Numerical simulations were performed using three wavefront distortion correction methods: time-shift compensation (TSC), backpropagation followed by ...
Deng-Huei, Huang, Jenho, Tsao
openaire   +2 more sources

Monolithic piezoelectric mirror for wavefront correction

Applied Physics Letters, 1974
Experimental and theoretical analysis show that a spatially varying potential applied to one surface of a thick block of piezoelectric material will induce a piezoelectric deformation of that surface proportional to the potential at each point of the surface.
J. Feinleib, S. G. Lipson, P. F. Cone
openaire   +1 more source

Wavefront correction inside unbalanced nulling interferometer

SPIE Proceedings, 2012
In an unbalanced nulling interferometer (UNI) of our coronagraph system, the incidence light is divided into two, and they interfere by a reverse phase with different amplitude. Thereby, phase errors are magnified and we can correct a wavefront with higher precision.
Masaaki Horie, Jun Nishikawa, Masahito Oya, Naoshi Murakami, Lyu Abe, Ryo Waki, Shiomi Kumagai, Motohide Tamura, Takashi Kurokawa, Hiroshi Murakami   +9 more
openaire   +1 more source

Tomagraphic wavefront correction for the LSST

SPIE Proceedings, 2006
The Large Synoptic Survey Telescope (LSST) is a three mirror modified Paul-Baker design with an 8.4m primary, a 3.4m secondary, and a 5.0m tertiary followed by a 3-element refractive corrector producing a 3.5 degree field of view. This design produces image diameters of
Phillion, D. W., Olivier, S. S., Baker, K., Seppala, L., Hvisc, S.   +4 more
openaire   +1 more source

Wavefront correction through image sharpness maximisation

SPIE Proceedings, 2005
A key component of any adaptive optics system (AO) for the correction of wavefront aberrations, is the wavefront sensor(WFS). Many systems operate in a mode where a WFS measures the aberrations present in the incoming beam. The required corrections are determined and applied by the wavefront corrector - often a deformable mirror (DM).
L. P. Murray, J. C. Dainty, E. Daly
openaire   +1 more source

Correction of large amplitude wavefront aberrations

SPIE Proceedings, 2005
Recently, a number of research groups around the world have developed ophthalmic instruments capable of in vivo diffraction limited imaging of the human retina. Adaptive optics was used in these systems to compensate for the optical aberrations of the eye and provide high contrast, high resolution images. Such compensation uses a wavefront sensor and a
S. A. Cornelissen, P. A. Bierden, T. G. Bifano, R. H. Webb, S. Burns, S. Pappas   +5 more
openaire   +1 more source

Wavefront correction by liquid-crystal devices

Soviet Journal of Quantum Electronics, 1986
An experimental investigation was made of the use of liquid-crystal phase correctors of wavefronts. Prototype correctors were prepared with independent addressing of the elements and these were found capable of compensating distortions of wavefronts of radiation of wavelengths 0.5–6μ.
A A Vasil'ev, A F Naumov, V I Shmal'gauzen   +2 more
openaire   +1 more source

Fundamentals of Ocular Wavefront Correction

2009
For vision correction, the key is to help patients achieve good visual performance. In most cases, this means good visual acuity and good contrast sensitivity. The ocular aberrations can be considered as a combination of the spherocylindrical aberrations and irregular aberrations.
openaire   +1 more source