Results 21 to 30 of about 504,859 (272)
Visible extreme adaptive optics for GMagAO-X with the triple-stage AO architecture (TSAO) [PDF]
Astronomical Telescopes + Instrumentation, 2022 The Extremely Large Telescopes will require hundreds of actuators across the pupil for high Strehl in the visible. We envision a triple-stage AO (TSAO) system for GMT/GMagAO-X to achieve this.
S. Haffert +5 more
semanticscholar +1 more source
Spatiotemporal statistics of the turbulent piston-removed phase and Zernike coefficients for two distinct beams. [PDF]
Journal of The Optical Society of America A-optics Image Science and Vision, 2021 In the context of adaptive optics for astronomy, one can rely on the statistics of the turbulent phase to assess a part of the system's performance. Temporal statistics with one source and spatial statistics with two sources are well known and widely ...
C. Plantet +3 more
semanticscholar +1 more source
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
openaire +3 more sources
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 A. +5 more
openaire +7 more sources
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
Confusion in differential piston measurement with the pyramid wavefront sensor
Astronomy & Astrophysics, 2021 Context. The pyramid was proven to be a highly sensitive and versatile wave-front sensor (WFS) and has been selected to be installed on the single conjugate adaptive optics (AO) systems of the extremely large telescope (ELT).
A. Bertrou-Cantou +6 more
semanticscholar +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
Adaptive Optics Correction of the Wavefront Distortions Induced by Segments Misalignment in Extremely Large Telescope [PDF]
, 2006 The capability of the adaptive optics to correct for the segmentation error is analyzed in terms of the residual wavefront RMS and the power spectral density of the phase.
Verinaud, Christophe, Yaitskova, Natalia
core +2 more sources
Optics Express, 2021 Coherent beam combination (CBC) holds promise for scaling the output power of the laser system while maintaining good beam quality. Owing to the thermal effect and mechanics instability, piston and tilt distortions always exist and affect the performance
Qi Chang +6 more
semanticscholar +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