Results 71 to 80 of about 19,057 (261)

Speckle noise reduction techniques for high-dynamic range imaging [PDF]

, 2007
High-dynamic range imaging from space in the visible, aiming in particular at the detection of terrestrial exoplanets, necessitates not only the use of a coronagraph, but also of adaptive optics to correct optical defects in real time.
Belikov, Belikov, Bordé, Bordé, Bordé, Codona, Dohlen, Give'on, Guyon, Guyon, Guyon, Kasdin, Kuchner, Lyot, Malbet, Pascal Bordé, Putnam, Roddier, Rouan, Shaklan, Traub, Trauger, Trauger, Wesley Traub   +23 more
core   +3 more sources

Accommodation to Wavefront Vergence and Chromatic Aberration [PDF]

Optometry and Vision Science, 2011
Longitudinal chromatic aberration (LCA) provides a cue to accommodation with small pupils. However, large pupils increase monochromatic aberrations, which may obscure chromatic blur. In this study, we examined the effect of pupil size and LCA on accommodation.Accommodation was recorded by infrared optometer while observers (nine normal trichromats ...
Yinan, Wang, Philip B, Kruger, James S, Li, Peter L, Lin, Lawrence R, Stark   +4 more
openaire   +2 more sources

Structural Eigenmodes of the Brain to Improve the Source Localization of EEG: Application to Epileptiform Activity

Advanced Science, EarlyView.
Geometry and connectivity are complementary structures, which have demonstrated their ability to represent the brain's functional activity. This study evaluates geometric and connectome eigenmodes as biologically informed constraints for EEG source localization.
Pok Him Siu, Philippa J. Karoly, Sina Mansour L., Artemio Soto‐Breceda, Levin Kuhlmann, Mark J. Cook, David B. Grayden   +6 more
wiley   +1 more source

Design of Eye Models for Quantitative Analysis of Interactions Between Ocular Aberrations and Intraocular Scattering

Photonics
Based on the widely used Gullstrand–Le Grand eye model, a scattering individual eye model was constructed with Zemax, which has individual ocular wavefront aberration and the scattering particles distributed in the eye.
Feng Rao, Lin Zhang, Xinheng Zhao, Jing Li, Jie Hou, Yan Wang   +5 more
doaj   +1 more source

Simultaneously measuring ocular aberration and anterior segment biometry during accommodation [PDF]

Journal of Innovative Optical Health Sciences, 2015
In the human eye, accommodation is essential for functional vision. However, the mechanisms regulating accommodation and the ocular parameters affecting aberrations remain to be explored.
Yuanyuan Wang, Yilei Shao, Yimin Yuan
doaj   +1 more source

Precise Wavefront Correction with an Unbalanced Nulling Interferometer for Exo-Planet Imaging Coronagraphs

, 2008
Very high dynamical range coronagraphs targeting direct exo-planet detection (10^9 - 10^10 contrast) at small angular separation (few lambda/D units) usually require an input wavefront quality on the order of ten thousandths of wavelength RMS. We propose
Abe, Aime, Baba, Baudoz, Bordé, Bracewell, Brown, Codona, Evans, Fienup, Galicher, Guyon, J. Nishikawa, Kasdin, Kuchner, L. Abe, Lowman, Malbet, Mennesson, N. Murakami, Nihsikawa, Riaud, Roggenmann, Shao, T. Kotani, Tamura, Tavrov, Tolls, Zernike   +28 more
core   +1 more source

Photon‐Sphere Modes in Curved Optical Microcavities: A Black‐Hole Analogue Laser

Advanced Science, EarlyView.
An optical analogue of a Schwarzschild black hole is realized using curved microcavities that preserve light‐like geodesics. A new family of laser modes confined around the photon sphere is identified alongside conventional whispering‐gallery modes. Analytical theory, numerical simulations, and experiments reveal curvature‐induced confinement, enabling
Chenni Xu, Aswathy Sundaresan, Nazire‐Begüm Kazkal, Clement Lafargue, Lior Zarfaty, Li‐Gang Wang, Ofek Birnholtz, Dominique Decanini, Melanie Lebental, Patrick Sebbah   +9 more
wiley   +1 more source

Focal-plane wavefront sensing with high-order adaptive optics systems

, 2014
We investigate methods to calibrate the non-common path aberrations at an adaptive optics system having a wavefront-correcting device working at an extremely high resolution (larger than 150x150).
Doelman, Niek, Keller, Christoph U., Kenworthy, Matthew, Korkiakoski, Visa, Otten, Gilles, Verhaegen, Michel   +5 more
core   +2 more sources

Depth-resolved wavefront aberrations using a coherence-gated Shack-Hartmann wavefront sensor [PDF]

Optics Express, 2010
In the present paper we investigate the possibility of narrowing the depth range of a physical Shack - Hartmann (SH) wavefront sensor (WFS) by using coherence gating. For the coherence gating, two low coherence interferometry (LCI) methods are evaluated and proof of principle configurations demonstrated: (i) a time domain LCI method based on phase ...
Tuohy, Simon, Podoleanu, Adrian G.H.
openaire   +2 more sources

Study of Free‐Space Optical Quantum Network: Review and Prospectives

Advanced Science, EarlyView.
Free from the constraints of fiber connections, free‐space quantum network enables longer and more flexible quantum network connections. This review summarizes and comparatively analyzes free‐space quantum network experiments based on ground stations, satellites, and mobile platforms.
Hua‐Ying Liu, Zhenda Xie, Shining Zhu
wiley   +1 more source