Results 181 to 190 of about 16,225 (252)
Recent Design and Application Advances in Micro-Electro-Mechanical System (MEMS) Electromagnetic Actuators. [PDF]
Micromachines (Basel)Cheng J +8 more
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Soft X-ray wavefront sensing at an ellipsoidal mirror shell. [PDF]
J Synchrotron RadiatBraig C +5 more
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Technologies for Fabricating Large-Size Diffraction Gratings. [PDF]
Sensors (Basel)Shao C, Li X.
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Cross-fringe piston sensor for segmented optics
Applied Optics, 2022 This paper presents a simple slit-mask-based sensing scheme that can be applied to a robust piston error sensor for segmented optical systems, even in space. Utilizing crossed fringes generated from multiple double-slit pairs, the sensor simultaneously detects multiple points in a segmented optical system in one shot. The experiments tested six pistons
Seichi Sato, Tadahito Mizutani
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Adaptive optics for array telescopes using piston-and-tilt wave-front sensing
Applied Optics, 1992 A near-infrared adaptive optics system operating at approximately 50 Hz has been used to control phase errors adaptively between two mirrors of the Multiple Mirror Telescope by stabilizing the position of the interference fringe in the combined unresolved far-field image.
Peter Wizinowich +8 more
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Considerations about the differential piston for adaptive optics interferometry
SPIE Proceedings, 2000 This contribution extends a previous work where the concept of piston angular anisoplanatism was introduced and the issue of sky-coverage for large ground-based optical interferometers was raised. We obtain expressions for the temporal power spectra of phase fluctuations caused by differential piston and photon noise.
Bruno Femenía +3 more
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Wide-range, high-accuracy, white light piston sensor for segmented optics
Optical Engineering, 1995 Optical systems with segmented mirrors require precision coalignment of their segments to attain the desired performance. A novel sensor for measuring piston over a ± 10 wave range by analyzing the image of a white light point source is described. The sensor combines a Young's two-slit aperture pair for coarse sensing with another set of apertures ...
Alan Wertheimer
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MEMS mirror with tip or piston motion for use in adaptive optics
The Journal of the Acoustical Society of America, 2008 An array of high fill factor mirrors has each mirror be coupled across two deformable spring bars that are deformed using a drive. The two deformable springs are parallel to each other, and coupled together, e.g., by a cross bar. A support is coupled at one end to the cross bar and at its opposite end to the mirror. Coupled across the deformable spring
Dennis S. Greywall
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<title>High-accuracy white-light optical piston sensor for segmented optics</title>
SPIE Proceedings, 1993 Alan Wertheimer, Thomas W. Dey
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