Results 221 to 230 of about 8,969 (258)

Measurement of the wavefront of XUV sources

Le Journal de Physique IV, 2001
New fields of x-ray sources applications (x-ray laser and High Order Harmonic Generation) could appear if an intensity higher than 10 12 Wcm -2 is reached. Following this goal, we have started a complete investigation of the x-ray beam wavefront both numerically and experimentally.
S. Le Pape, Ph. Zeitoun, J.-F. Hergot, B. Carré, P. Dhez, M. François, M. Idir, H. Merdji, D. Ros, A. Carillon, P. Salières   +10 more
openaire   +1 more source

MEASUREMENT OF THE AXIAL WAVEFRONT ABERRATION OF THE HUMAN EYE

Ophthalmic and Physiological Optics, 1985
Abstract— An objective variation of Howland and Howland's subjective crossed‐cylinder aberroscope method of estimating ocular aberration is described. An ophthalmoscopic arrangement allows the distorted retinal image of the aberroscope grid to be directly photographed for later analysis.
G, Walsh, W N, Charman
openaire   +2 more sources

The Effect of Phenylephrine and Cyclopentolate on Objective Wavefront Measurements

Journal of Refractive Surgery, 2006
ABSTRACT PURPOSE: To investigate the impact of phenylephrine and cyclopentolate on wavefront refraction and fourth order spherical aberration C 12 . METHODS: This cohort study comprised 151 eyes with sphere up to -10.00 diopters (D) and cylinder -3.75 D. Aberrometry was performed using
Mirko R, Jankov, Hans Peter, Iseli, Michael, Bueeler, Paulo, Schor, Theo, Seiler, Michael, Mrochen   +5 more
openaire   +2 more sources

Objective Measurement of Wavefront Aberrations With and Without Accommodation

Journal of Refractive Surgery, 2001
ABSTRACT PURPOSE: The measurement of the refractive error profile is more useful than corneal topography in understanding the complexities of refractive surgery. We report on experimental studies of the spatially resolved refractometer Tracey-1, developed in Ukraine by IBME in medical cooperation with VEIC, Greece. METHODS: Ten eyes
L G, Pallikaris, S I, Panagopoulou, C S, Siganos, V V, Molebny   +3 more
openaire   +2 more sources

Hartmann sensor for wavefront measurements at terahertz frequencies

2013 38th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz), 2013
The measurement of the wavefront of a terahertz (THz) beam is essential for the development of any optical instrument operating at THz frequencies. We have realized a Hartmann wavefront sensor for the THz frequency range. The sensor is based on an aperture plate consisting of a regular square pattern of holes and a microbolometer camera.
Richter, Heiko, Greiner-Bär, Michael, Deßmann, N., Pfund, Johannes, Wienold, Martin, Schrottke, Lutz, Grahn, H. T., Hübers, Heinz-Wilhelm   +7 more
openaire   +2 more sources

Wavefront measurement based on sparse aperture

Optical Design and Testing X, 2020
Large aperture optical system is more and more widely used in astronomy and space optics. With the increase of aperture, the detection methods and instruments are faced with many challenges. It is difficult for traditional full-aperture detection to meet the requirements of modern large-aperture optical system.
Jingwen Xu, Yun Wang, Xin Dong
openaire   +1 more source

Wavefront Distortion Measurement at SSRF

2017
Proceedings of the 8th Int.
Gao, Bo, Chen, Hanjiao, Chen, Jie, Leng, Yongbin, Ye, Kairong, Zhang, Ning   +5 more
openaire   +1 more source

Visualization and measurement of ultrasonic wavefronts

Proceedings of the IEEE, 1979
The transmission of ultrasonic wavefronts through a medium and the reflection of these wavefronts from an object or interface depend upon the bulk mechanical properties of the medium or object. Measuring or visualizing the wavefront yields important information about various transmission media and objects under study and has found application in ...
openaire   +1 more source

Wavefront measurements on semiconductor lasers

IEEE Journal of Quantum Electronics, 1983
Two-dimensional phase measurements of the far field of semiconductor lasers have been performed. An accuracy of one fiftieth of a wavelength has been obtained. In this paper, we will briefly describe the method used and present some results. It was possible to determine the neat-field behavior of both the amplitude and the phase from the measured fat ...
openaire   +1 more source

Reliability of Corneal and Total Wavefront Aberration Measurements With the SCHWIND Corneal and Ocular Wavefront Analyzers

Journal of Refractive Surgery, 2006
ABSTRACT PURPOSE: To evaluate the reliability of the SCHWIND Corneal and Ocular Wavefront Analyzers. METHODS: This study comprised 115 eyes of 58 healthy volunteers (26 [44.8%] women and 32 [55.2%] men) with no corneal or lenticular pathologies and normal visual acuity.
Mike P, Holzer, Martin, Sassenroth, Gerd U, Auffarth   +2 more
openaire   +2 more sources