Results 211 to 220 of about 16,325 (263)

Piston alignment of segmented optical mirrors via convolutional neural networks

Optics Letters, 2018
Most of the methods used today for the alignment of segmented mirrors are based on Shack-Hartman wavefront sensors. Other proposed methods are based on curvature sensors. These can be used to cross-check the measurements given by the primary method. We investigate a different approach which employs convolutional neural networks.
Dailos, Guerra-Ramos, Lara, Díaz-García, Juan, Trujillo-Sevilla, Jose Manuel, Rodríguez-Ramos   +3 more
openaire   +2 more sources

A piston error detection method of optical synthetic aperture system

SPIE Proceedings, 2014
The existence of phase error influences the imaging performance of optical synthetic aperture system and limits the resolution of the imaging system. The relationship between point spread function of binocular system and piston error is analyzed and the conclusion that the relation between point spread function and piston error is irrational with ...
Xiaofeng Wei, Zexun Geng, Chao Jiang, Chubin Liu   +3 more
openaire   +1 more source

The optical piston in a capillary cell with open ends

Journal of Physics B: Atomic, Molecular and Optical Physics, 1988
The authors present measurements of the time evolution of the spatial density distribution of Na atoms in an argon buffer gas, inside a capillary cell with open ends. The entrance of the capillary is irradiated with a laser beam that fills its cross section, so that light-induced drift occurs. For sufficiently high intensity, a steep front may build up,
H G C Werij, G Nienhuis, J P Woerdman
openaire   +1 more source

Two Dimensional MEMS Piston Array for DUV Optical Pattern Generation

IEEE/LEOS International Conference on Optical MEMS and Their Applications Conference, 2006., 2006
We describe the design, fabrication and dynamics of a two dimensional array of MEMS piston mirrors that fulfil the requirements needed to modulate deep ultraviolet radiation for mask pattern ...
D. Lopez, F. Pardo, C. Bolle, N. Basavanhally, J. Bower, J. Miner, T. Sorsch, D. Tennant, V. Aksyuk, G. Watson, M.E. Simon, W. Mansfield, F. Klemens, R. Cirelli, E. Ferry, A. Papazian   +15 more
openaire   +1 more source

Coupled waveguide integrated optic segment piston sensor for the GMT

2013 Conference on Lasers & Electro-Optics Europe & International Quantum Electronics Conference CLEO EUROPE/IQEC, 2013
Integrated optic segment piston sensor (IOPS) for the Giant Magellan Telescope (GMT) uses single mode laser written waveguides to measure segment piston (axial alignment) of the GMT primary mirrors. Light in the H-band (from 1.5 to 1.6 μm) incident on each segment originating from an off-axis guide star is coupled into separate laser written single ...
Francis Bennet, Kristina Uhlendorf, Rusty Gardhouse, Rodolphe Conan, Brady Espeland, Antonin Bouchez   +5 more
openaire   +1 more source

Optical Ways to Improve the Tribological System Piston - Ring - Liner

SAE Technical Paper Series, 2006
<div class="htmlview paragraph">The reliable function of the system piston - piston ring -liner depends strongly on the correct quantity of oil. A balance between the sufficient oil offer and minimum emission is to be found. For this system numerous computation programs exist however their results strongly depends from the boundary conditions. To
Uwe Todsen, Kai Uwe Niethus
openaire   +1 more source

Modeling of the optical piston: Density-wave shape and resonance-fluorescence effects

Physical Review A, 1988
We present results of a numerical model of the optical piston driven by laser-induced drift (LID). The model is based on a drift-velocity formulation of Lawandy, derived from an asymmetric-random-walk argument, and includes resonance-fluorescence effects. The model is applied primarily to the experimental conditions of H. G. C.
, Calo, , Lawandy, , Frezzo, , Perkins
openaire   +2 more sources

MEMS tip/tilt and piston mirror arrays as diffractive optical elements

SPIE Proceedings, 2005
We present an analytic evaluation of the optical performance of a tip/tilt and piston Spatial Light Modulator, for use in adaptive optic and beam steering applications. The impact of array fill factor, pixel curvature, position and tilt accuracy, and pixel yield are discussed in detail.
Roland Ryf, Howard R. Stuart, C. R. Giles   +2 more
openaire   +1 more source

A Tip-Tilt-Piston Micromirror Array for Optical Phased Array Applications

Journal of Microelectromechanical Systems, 2010
A tip-tilt-piston micromirror array based on electrothermal bimorph actuation is presented. The micromirror uses a compactly folded actuator design that can realize high fill-factor with a simple fabrication process. A 4 × 4 micromirror array with sub-apertures of 0.9 mm and a fill-factor of 54% is demonstrated.
Lei Wu, Sarah Dooley, Edward A. Watson, Paul F. McManamon, Huikai Xie   +4 more
openaire   +1 more source

Analysis of piston error of an optical sparse-aperture imaging system

SPIE Proceedings, 2009
With the development of Earth and Space missions, the quest for higher spatial resolution for telescopes will turn into urgent need. Optical sparse-aperture system can be designed to obtain high resolution in astronomical object imaging with several independent small-aperture telescopes.
Juan Zhao, Dayong Wang, Zhiwei Zhou, Yuhong Wan, Zhuqing Jiang, Shiquan Tao   +5 more
openaire   +1 more source