Results 91 to 100 of about 2,401,843 (348)

Image-based wavefront sensing for astronomy using neural networks

open access: yesJournal of Astronomical Telescopes Instruments and Systems, 2020
. Motivated by the potential of nondiffraction limited, real-time computational image sharpening with neural networks in astronomical telescopes, we studied wavefront sensing with convolutional neural networks based on a pair of in-focus and out-of-focus
T. Andersen   +2 more
semanticscholar   +1 more source

Ellipticity‐Controlled Exceptional Points and Cross‐Polarized Phase Singularities in Multi‐Layer Silicon Guided Mode Resonant Metasurfaces

open access: yesAdvanced Optical Materials, EarlyView.
Omni‐polarizers that pull all input polarization states to an elliptical or linear polarization can be made using highly resonant bi‐layer metasurfaces. The ellipticity of the selected polarization can be controlled by choosing the layer separation.
Ben Goldberg   +2 more
wiley   +1 more source

Wavefront Sensing by a Common-Path Interferometer for Wavefront Correction in Phase and Amplitude by a Liquid Crystal Spatial Light Modulator Aiming the Exoplanet Direct Imaging

open access: yesPhotonics, 2023
We implemented the common-path achromatic interfero-coronagraph both for the wavefront sensing and the on-axis image component suppression, aiming for the stellar coronagraphy.
Andrey Yudaev   +5 more
doaj   +1 more source

Curvature Wavefront Sensing for the Large Synoptic Survey Telescope

open access: yes, 2015
The Large Synoptic Survey Telescope (LSST) will use an active optics system (AOS) to maintain alignment and surface figure on its three large mirrors.
Angeli, George   +5 more
core   +1 more source

Picometer wavefront sensing using the phase-contrast technique

open access: yes, 2020
Precision wavefront sensing and interferometry are essential in many fields of industry and fundamental research. Characterization of semiconductor devices, optics in lithography systems, and biologic features of living cells all require measurement ...
John B. Steeves   +3 more
semanticscholar   +1 more source

Topology Optimization Enables Freeform Matrix Fourier Optics

open access: yesAdvanced Optical Materials, EarlyView.
A topology‐optimized freeform metasurface is designed and fabricated to realize matrix Fourier optics, enabling the diffraction of multiple polarization states into distinct far‐field orders. By combining forward design with gradient‐based inverse optimization, high polarization contrast of up to 98.7% is achieved.
Yu‐Tzu Liu   +5 more
wiley   +1 more source

Efficient decoding of 2D structured illumination with linear phase stepping in X-ray phase contrast and dark-field imaging. [PDF]

open access: yesPLoS ONE, 2014
The ability to map the phase distribution and lateral coherence of an x-ray wavefront offers the potential for imaging the human body through phase contrast, without the need to deposit significant radiation energy. The classic means to achieve this goal
Katherine J Harmon   +3 more
doaj   +1 more source

The coronagraphic Modal Wavefront Sensor: a hybrid focal-plane sensor for the high-contrast imaging of circumstellar environments [PDF]

open access: yes, 2016
The raw coronagraphic performance of current high-contrast imaging instruments is limited by the presence of a quasi-static speckle (QSS) background, resulting from instrumental non-common path errors (NCPEs).
Keller, Christoph U.   +4 more
core   +3 more sources

High‐Isolation LCoS‐Based Optical Switch with Phase Hologram Parameter Optimization

open access: yesAdvanced Photonics Research, EarlyView.
A 1 × 9 liquid crystal on silicon (LCoS)‐based optical switch is experimentally demonstrated, revealing that the worst‐case port isolation exceeds 37 dB within the wavelength range of 1460–1540 nm. This work offers an alternative route for the development of optical switches with a large number of ports and high isolation, applicable to large‐capacity ...
Linbojie Huang   +8 more
wiley   +1 more source

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