Results 201 to 210 of about 30,065 (244)

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

A discussion of two wavefront aberration correction procedures

Ultrasonic Imaging, 1992
This review paper discusses the basic properties of two adaptive signal processing procedures for dealing with weak scattering in a phased array transducer system. A fundamental improvement in the lateral resolution of ultrasonic echo scanners will result if the weight vector of a large phased array transducer can be modified to account for distortion
openaire   +2 more sources

EXACT WAVEFRONT CORRECTION IN ADAPTIVE OPTICS

IFAC Proceedings Volumes, 2005
Abstract In this work we consider an adaptive optical system in which a deformable mirror is controlled to compensate for random wavefront disturbances. For most systems of this type, the shape of the mirror is taken as a linear function of the wavefront error, leading to satisfactory results in linear regimes.
Pierre Le Gall, Lionel Rosier
openaire   +1 more source

Liquid deformable mirror for high-order wavefront correction

Optics Letters, 2006
We propose and demonstrate a novel liquid deformable mirror, based on electrocapillary actuation, for high-order wavefront correction. The device consists of a two-dimensional array of vertically oriented microchannels filled with two immiscible liquids, an aqueous electrolyte, and a viscous dielectric liquid, where the dielectric liquid overfills the ...
Vuelban, E.M. (author), Bhattacharya, N. (author), Braat, J.J.M. (author)   +2 more
openaire   +4 more sources