Results 331 to 340 of about 7,907,205 (365)

Theory and design of line-to-point focus solar concentrators with tracking secondary optics.

Applied Optics, 2013
The two-stage line-to-point focus solar concentrator with tracking secondary optics is introduced. Its design aims to reduce the cost per m(2) of collecting aperture by maintaining a one-axis tracking trough as the primary concentrator, while allowing ...
T. Cooper, G. Ambrosetti, A. Pedretti, A. Steinfeld   +3 more
semanticscholar   +1 more source

Focus-wavelength encoded optical profilometer

Optics Communications, 1984
Abstract An optical profilometer is presented working on the principle of focus multiplexing by wavelength encoding. Decoding is performed by lateral dispersion. A detector array shows up a signal distribution whose features accurately monitor the surface position of the sample under test.
G Molesini, G Pedrini, P Poggi, F Quercioli   +3 more
openaire   +3 more sources

Scattering in focus

Nature Photonics, 2013
Sustaining the ongoing revolution in optical microscopy will require gaining detailed insight into the optical fields in focal spots. Researchers have developed an elegant method for mapping the full electric vector field using just a metal nanosphere on a glass substrate.
openaire   +2 more sources

A Comparative Evaluation of a New Generation of Diffractive Trifocal and Extended Depth of Focus Intraocular Lenses.

Journal of refractive surgery, 2018
PURPOSE To evaluate and compare the performance of two diffractive trifocal and one extended depth of focus (EDOF) intraocular lenses (IOLs). METHODS In this 6-month, single-center, prospective, randomized, comparative study, patients undergoing ...
B. Cochener, G. Boutillier, M. Lamard, Claire Auberger-Zagnoli   +3 more
semanticscholar   +1 more source

Accurate shape from focus based on focus adjustment in optical microscopy

Microscopy Research and Technique, 2008
AbstractOptical microscopy allows a magnified view of the sample while decreasing the depth of focus. Although the acquired images from limited depth of field have both blurred and focused regions, they can provide depth information. The technique to estimate the depth and 3D shape of an object from the images of the same sample obtained at different ...
Seong-O Shim, Aamir Saeed Malik, Tae-Sun Choi   +2 more
openaire   +3 more sources

Dual focus diffractive optical element with extended depth of focus

Optical Review, 2014
A dual focus property and an extended depth of focus were verified by a new type of diffractive lens displaying on liquid crystal on silicon (LCoS) devices. This type of lens is useful to read information on multilayer optical discs and tilted discs. The radial undulation of the phase groove on the diffractive lens gave the dual focus nature. The focal
Katsuhiro Uno, Isao Shimizu
openaire   +2 more sources

Quasi In-Focus Optical Coherence Tomography

Japanese Journal of Applied Physics, 2004
We propose here a unique method for in-focus imaging over the entire cross-sectional area of interest. This is the so-called quasi in-focus optical coherence tomography (OCT) or multiple OCT in which OCT images are obtained by shifting the focal plane of an objective, followed by piling up of these OCT images.
Masato Ohmi, Takayuki Kurata, Mitsugu Sekimoto, Masamitsu Haruna   +3 more
openaire   +2 more sources

Energy backflow in the focus of an optical vortex

Laser Physics, 2018
By employing Richards-Wolf formulae for an aplanatic system, we show that when tightly focusing a left-hand circularly polarized optical vortex with the topological charge 2 and an arbitrary apodization function, an on-axis energy backflow occurs in the focus plane, which is verified by a negative optical-axis projection of the Poynting vector.
Anton G. Nalimov, Anton G. Nalimov, Sergey S. Stafeev, Sergey S. Stafeev, Victor V. Kotlyar, Victor V. Kotlyar   +5 more
openaire   +2 more sources

Deep tissue multi-photon imaging using adaptive optics with direct focus sensing and shaping

Nature Biotechnology, 2022
Zhongya Qin, Zhentao She, Congping Chen, Wanjie Wu, Jackie K. Y. Lau, N. Ip, J. Qu   +6 more
semanticscholar   +1 more source

Diffraction depth of focus in optical microscope

SPIE Proceedings, 2010
The paper presents the mathematical technique for calculation of the diffraction depth of focus of an optical system of a widefield microscope. The proposed technique applies the Rayleigh criterion based on evaluation of the wave aberration appeared due to defocus in a high aperture optical system.
Volodymyr N. Borovytsky, Andrey V. Fesenko   +1 more
openaire   +2 more sources