Results 21 to 30 of about 3,034 (156)

Wide-Field Telescope Alignment Using the Model-Based Method Combined with the Stochastic Parallel Gradient Descent Algorithm

open access: yesPhotonics, 2021
To acquire images with higher accuracy of wide-field telescopes, deformable mirrors with more than 100 actuators are used, making the telescope alignment more complex and time-consuming.
Min Li, Ang Zhang, Junbo Zhang, Hao Xian
doaj   +1 more source

Stroke amplifier for deformable mirrors [PDF]

open access: yesApplied Optics, 2004
We demonstrate a simple optical configuration that amplifies the usable stroke of a deformable mirror. By arranging for the wavefront to traverse the deformable mirror more than once, we correct it more than once. The experimental implementation of the idea demonstrates a doubling of 2.0 and 2.04 by two different means.
Robert H, Webb   +4 more
openaire   +2 more sources

Active Optics–Freeform Segment Mirror Replications from a Deformable Matrix

open access: yesPhotonics, 2022
We present a new active optics method for making smooth aspheric, or freeform, mirrors by replication technique from an elastically deformable matrix.
Gerard R. Lemaitre, Patrick Lanzoni
doaj   +1 more source

A direct comparison between a MEMS deformable mirror and a liquid crystal spatial light modulator in signal-based wavefront sensing [PDF]

open access: yesJournal of the European Optical Society-Rapid Publications, 2013
Aberrations degrade the performance of optical systems in terms of resolution and signal-to-noise ratio. This work explores the feasibility of a signal-based wavefront sensor, which employs a search algorithm to estimate Zernike coefficients of given ...
Jewel A. R., Akondi V., Vohnsen B.
doaj   +1 more source

Calibration and performance evaluation of a monomorph deformable mirror

open access: yesResults in Optics, 2022
To achieve diffraction-limited performance with a 50 cm solar telescope at the Udaipur solar observatory the development of a high-order adaptive optics (AO) system is currently in progress. The system includes a monomorph deformable mirror (MDM) with 85
A. Raja Bayanna   +3 more
doaj   +1 more source

Literature Review on Adaptive Optics [PDF]

open access: yesINCAS Bulletin
Adaptive optics (AO) is defined as a technology developed to compensate for wavefront distortions caused by atmospheric turbulence or microscopic heterogeneities, thereby enhancing image quality in observational astronomy and biological microscopy.
Muaayed F. AL-RAWI, Mhnd FARHAN
doaj   +1 more source

CIAO: An on-the-shelf adaptive optics system for astronomers [PDF]

open access: yesEPJ Web of Conferences, 2023
Since 1990, adaptive optics are used in astronomy to remove the effects of atmospheric turbulence, and then retrieve diffraction-limited images, even in bad seeing conditions.
Dovillaire Guillaume, Leveder Cora
doaj   +1 more source

Active Optics in Astronomy: Freeform Mirror for the MESSIER Telescope Proposal

open access: yesMathematical and Computational Applications, 2018
Active optics techniques in astronomy provide high imaging quality. This paper is dedicated to highly deformable active optics that can generate non-axisymmetric aspheric surfaces—or freeform surfaces—by use of a minimum number of actuators ...
Gerard Rene Lemaitre   +2 more
doaj   +1 more source

A Lorentz Force Actuated Continuous Deformable Polymer Mirror for Wavefront Control

open access: yesProceedings, 2017
This paper describes MEMS deformable polymer mirror system for adaptive optics application. This system employs a 4 µm thick SU-8 membrane with a stress balanced double side aluminum coating as a mirror element.
Byoungyoul Park   +2 more
doaj   +1 more source

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