Results 61 to 70 of about 5,531 (246)

Multi‐Channel Electrically Tunable Varifocal Metalens With Compact Multilayer Polarization‐Dependent Metasurfaces and Liquid Crystals

open access: yesAdvanced Science, EarlyView.
A compact eight‐channel electrically tunable varifocal metalens with three single‐layer polarization‐multiplexed bi‐focal metalens and three LC cells. The total thickness of the device is ∼6 mm, while the focal lengths can be switched among eight values (3.6, 4.2, 4.5, 4.9, 6.2, 6.9, 8.4, and 9.6 mm). ABSTRACT As an essential module of optical systems,
Zhiyao Ma   +11 more
wiley   +1 more source

Wavefront Sensor for Laser Beams Based on Reweighted Amplitude Flow Algorithm

open access: yesApplied Sciences
We present a reference-free computational wavefront sensor based on binary amplitude modulation and phase retrieval. The method employs a Digital Micromirror Device as a programmable amplitude modulator and reconstructs the complex optical field from ...
Ondřej Denk   +4 more
doaj   +1 more source

Micro-machined membrane deformable mirrors for cryogenic adaptive optics [PDF]

open access: yes, 2002
In this Thesis, the suitability of 37 actuator Micro-machined membrane deformable mirrors (MMDM) for adaptive optics at cryogenic temperatures is evaluated. A method is described to safely cool MMDMs to 78K. The initial surface figures of three MMDMs are
Dyson, H.M., Dyson, Harold Michael
core  

SWaRP: Speckle Wavefront Reconstruction Package – User Manual

open access: yes, 2018
SWaRP (Speckle Wavefront Reconstruction Package ) is a numerical tool intended for wavefront recovery and reconstruction in both differential and absolute metrology modes, based on the X-ray Speckle Tracking (XST) principle.
Berujon, Sebastien (8192097)   +5 more
core   +1 more source

Wavefront Line‐Scan Imaging Via a Single‐Pixel Detector

open access: yesAdvanced Science, EarlyView.
We propose and demonstrate a wavefront line‐scan imaging paradigm that integrates 1D spatial light modulation with single‐pixel detection. Benefiting from 1D modulation, not only is the imaging speed improved, but also the storage of modulation patterns is reduced by several orders of magnitude.
Nuo Liu   +4 more
wiley   +1 more source

Deep learning enabled robust wavefront sensing for active beam smoothing with a continuous phase modulator

open access: yesHigh Power Laser Science and Engineering
In laser systems requiring a flat-top distribution of beam intensity, beam smoothing is a critical technology for enhancing laser energy deposition onto the focal spot.
Yamin Zheng   +9 more
doaj   +1 more source

Metasurface‐Enabled Active‐Like Passive Radar

open access: yesAdvanced Science, EarlyView.
A programmable space‐time‐coding metasurface embeds distinct spatiotemporal tags into ambient wireless signals, allowing passive radar to operate in an active‐like manner. By enabling code‐correlated reconstruction under interference, the approach supports robust real‐time UAV tracking in complex environments and points to intelligent, low‐power ...
Mingyi Li   +7 more
wiley   +1 more source

Contour generation by wavefront reconstruction [PDF]

open access: yesPhysics Letters, 1965
Peer Reviewed ; http://deepblue.lib.umich.edu/bitstream/2027.42/31977/1/0000019 ...
Haines, K. A., Hildebrand, B. P.
openaire   +2 more sources

TRIM: Simultaneous Thermometry, Ranging, and Imaging via a Monolithic Metalens

open access: yesAdvanced Science, EarlyView.
ABSTRACT While metasurfaces offer a pathway beyond the discrete architectures of conventional LWIR systems, physically fusing high‐precision thermometry and passive ranging onto a single metalens remains a formidable challenge. Here, we demonstrate a monolithic, dual‐focus metalens capable of simultaneous multidimensional sensing.
Man Yuan   +10 more
wiley   +1 more source

Cross-scale inference and wavefront reconstruction

open access: yes, 2014
International audienceWe introduce a new approach to wavefront phase reconstruction in Adaptive Optics using a non-linear approach derived from the Microcanonical Multiscale Formalism (MMF).
Maji, Suman Kumar   +2 more
core   +3 more sources

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