Results 1 to 10 of about 16,325 (263)
Micromachines, 2022 Phase light modulator (PLM) by MEMS mirror array operating in a piston-mode motion enables a high-speed diffractive beam steering in a random-access and flexible manner that makes a lidar system more intelligent and adaptive.
Jiafan Guan +3 more
doaj +1 more source
Piston Error Measurement for Segmented Telescopes with an Artificial Neural Network
Sensors, 2021 A piston error detection method is proposed based on the broadband intensity distribution on the image plane using a back-propagation (BP) artificial neural network.
Dan Yue, Yihao He, Yushuang Li
doaj +1 more source
In-Situ Metrology of Large Segmented Detector Based on Modified Optical Truss
IEEE Photonics Journal, 2023 To precisely map cosmic structures and capture time-domain events, future large survey telescopes will be equipped with segmented detectors that greatly expand their field of view. Segment flatness and assembly accuracy will be essential for them to make
Qichang An +6 more
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APL Photonics, 2020 Adaptive optics (AO) methods are widely used in microscopes to improve image quality through correction of phase aberrations. A range of wavefront-sensorless AO schemes exist, such as modal, pupil segmentation zonal, and pixelated piston-based methods ...
Q. Hu +7 more
doaj +1 more source
Phasing the Mirror Segments of the Keck Telescopes: The Broadband Phasing Algorithm [PDF]
, 1998 To achieve its full diffraction limit in the infrared, the primary mirror of the Keck telescope (now telescopes) must be properly phased: The steps or piston errors between the individual mirror segments must be reduced to less than 100 nm. We accomplish
Chanan, Gary +6 more
core +1 more source
Spatial Spectrum Analysis of Wave-Front Correction with a Segmented Mirror [PDF]
, 2003 An expression is derived for the spatial power spectrum of wave-front errors after correction with a segmented mirror. This includes estimates of the spectral contributions of segment piston and tilt corrections and spatial aliasing by a regular array of
Padin, Stephen
core +1 more source
Oil Film Formation of Reciprocating Seals Observed by Interferometry
Tribology Online, 2014 Oil film thickness in rubber piston seals is measured by interferometry. Optimized optics and fluids enable clear interferograms. The oil film thickness on the contact area is measured during reciprocating motion.
Kenichi Yoshimura +2 more
doaj +1 more source
Sensors, 2010 Since the beginning of the Mars planet exploration, the characterization of carbon dioxide hypersonic flows to simulate a spaceship’s Mars atmosphere entry conditions has been an important issue.
Raphäel Vallon +5 more
doaj +1 more source
High-performance 3D waveguide architecture for astronomical pupil-remapping interferometry [PDF]
, 2014 The detection and characterisation of extra-solar planets is a major theme driving modern astronomy, with the vast majority of such measurements being achieved by Doppler radial-velocity and transit observations.
Charles, Ned +8 more
core +1 more source
Tests with a Carlina-type diluted telescope; Primary coherencing [PDF]
, 2012 Studies are under way to propose a new generation of post-VLTI interferometers. The Carlina concept studied at the Haute- Provence Observatory is one of the proposed solutions. It consists in an optical interferometer configured like a diluted version of
A. Le Vansuu +37 more
core +3 more sources