Results 1 to 10 of about 16,225 (252)
Piston control with adaptive optics in stellar interferometry [PDF]
Astronomy & Astrophysics, 2001 The general purpose of an adaptive optics system is to correct for the wavefront corrugations due to atmospheric turbulence. When applied to a stellar interferometer, care must be taken in the control of the mean optical path length, commonly called differential piston.
C. Vérinaud, F. Cassaing
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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
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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
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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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Piston-Type Optical Modulator for Dynamic Thermal Radiation Tuning Applications [PDF]
Materials, 2021 This study introduces a movable piston-like structure that provides a simple and cost-effective avenue for dynamically tuning thermal radiation. This structure leverages two materials with dissimilar optical responses—graphite and aluminum—to modulate from a state of high reflectance to a state of high absorptance.
Andrew Caratenuto, Yi Zheng
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Dynamics of photon fluid flows driven by optical pistons [PDF]
Conference on Lasers and Electro-Optics, 2019 The piston problem, i.e. the dynamics of a uniform gas at rest under the action of a moving piston, is fundamental in shock wave physics [1,2]. In conservative systems, shock waves are regularized by the formation, owing to dispersion, of rapidly oscillating non-stationary structures, called dispersive shock waves (DSWs) [3–6].
Bendahmane, Abdelkrim +5 more
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Optical fiber analogous of the piston shock problem [PDF]
Advanced Photonics 2018 (BGPP, IPR, NP, NOMA, Sensors, Networks, SPPCom, SOF), 2018 We investigate the optical analogous of the piston shock problem in gas dynamics. Using fast temporal measurements, we recorded dispersive shock waves formed by the propagation of a bi-chromatic photon fluid along an optical fiber.
Bendahmane, Abdelkrim +5 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
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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
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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
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