scholarly journals Wide-field AO correction: the large wavefront sensor detector of ARGOS

2010 ◽  
Author(s):  
Gilles Orban de Xivry ◽  
Sebastian Rabien ◽  
Lothar Barl ◽  
Simone Esposito ◽  
Wolfgang Gaessler ◽  
...  
Keyword(s):  
Wavefront Sensor ◽  
Wide Field

A very wide field wavefront sensor for a very narrow field interferometer

2010 ◽  
Author(s):  
V. Viotto ◽  
R. Ragazzoni ◽  
C. Arcidiacono ◽  
M. Bergomi ◽  
A. Brunelli ◽  
...  
Keyword(s):  
Wavefront Sensor ◽  
Wide Field

Adaptive optics wide-field microscope corrections using a MEMS DM and Shack-Hartmann wavefront sensor

2011 ◽  
Author(s):  
Oscar Azucena ◽  
Xiaodong Tao ◽  
Justin Crest ◽  
Shaila Kotadia ◽  
William Sullivan ◽  
...  
Keyword(s):  
Adaptive Optics ◽  
Wavefront Sensor ◽  
Wide Field

scholarly journals DO-CRIME: Dynamic On-sky Covariance Random Interaction Matrix Evaluation, a novel method for calibrating adaptive optics systems

2020 ◽  
Author(s):  
Olivier Lai ◽  
Mark Chun ◽  
Ryan Dungee ◽  
Jessica Lu ◽  
Marcel Carbillet
Keyword(s):  
Adaptive Optics ◽  
Calibration Procedure ◽  
Wavefront Sensor ◽  
Interaction Matrix ◽  
Wide Field ◽  
Secondary Mirror ◽  
Novel Method ◽  
Measurement Vector ◽  
Random Patterns ◽  
Interaction Matrices

Abstract Adaptive optics systems require a calibration procedure to operate, whether in closed loop or even more importantly in forward control. This calibration usually takes the form of an interaction matrix and is a measure of the response on the wavefront sensor to wavefront corrector stimulus. If this matrix is sufficiently well conditioned, it can be inverted to produce a control matrix, which allows to compute the optimal commands to apply to the wavefront corrector for a given wavefront sensor measurement vector. Interaction matrices are usually measured by means of an artificial source at the entrance focus of the adaptive optics system; however, adaptive secondary mirrors on Cassegrain telescopes offer no such focus and the measurement of their interaction matrices becomes more challenging and needs to be done on-sky using a natural star. The most common method is to generate a theoretical or simulated interaction matrix and adjust it parametrically (for example, decenter, magnification, rotation) using on-sky measurements. We propose a novel method of measuring on-sky interaction matrices ab initio from the telemetry stream of the AO system using random patterns on the deformable mirror with diagonal commands covariance matrices. The approach, being developed for the adaptive secondary mirror upgrade for the imaka wide-field AO system on the UH2.2m telescope project, is shown to work on-sky using the current imaka testbed.

Laboratory quantification of a plenoptic wavefront sensor with extended objects

2020 ◽  
Vol 497 (4) ◽  
pp. 4580-4586
Author(s):  
Zhentao Zhang ◽  
Nazim Bharmal ◽  
Tim Morris ◽  
Yonghui Liang
Keyword(s):  
Adaptive Optics ◽  
Closed Loop ◽  
Optical Design ◽  
Wavefront Sensor ◽  
Wavefront Sensing ◽  
Wide Field ◽  
Loop Correction ◽  
Wavefront Correction ◽  
Set Up ◽  
Experimental Bench

ABSTRACT Adaptive optics (AO) is widely used in ground-based telescopes to compensate the effects of atmosphere distortion, and the wavefront sensor is a significant component in the AO systems. The plenoptic wavefront sensor has been proposed as an alternative wavefront sensor adequate for extended objects and wide field of views. In this paper, a experimental bench has been set up to investigate the slope measurement accuracy and closed-loop wavefront correction performance for extended objects. From the experimental results, it has been confirmed that plenoptic wavefront sensor is suitable for extended objects wavefront sensing with proper optical design. The slope measurements have a good linearity and accuracy when observing extended objects. The image quality is significantly improved after closed-loop correction. A method of global tip/tilt measurement using only plenoptic wavefront sensor frame is proposed in this paper, it is also a potential advantage of plenoptic wavefront sensor in extended objects wavefront sensing.

scholarly journals Experience with wavefront sensor and deformable mirror interfaces for wide-field adaptive optics systems

2016 ◽  
Vol 459 (2) ◽  
pp. 1350-1359 ◽  
Author(s):  
A. G. Basden ◽  
D. Atkinson ◽  
N. A. Bharmal ◽  
U. Bitenc ◽  
M. Brangier ◽  
...  
Keyword(s):  
Adaptive Optics ◽  
Wavefront Sensor ◽  
Deformable Mirror ◽  
Wide Field

Characterizing daytime wind profiles with the wide-field Shack–Hartmann wavefront sensor

2019 ◽  
Vol 483 (4) ◽  
pp. 4910-4921
Author(s):  
Zhiyong Wang ◽  
Lanqiang Zhang ◽  
Changhui Rao
Keyword(s):  
Wavefront Sensor ◽  
Wide Field ◽  
Wind Profiles

Multiple-object Shack–Hartmann wavefront sensor design for a wide field of view on the retina

2015 ◽  
Vol 13 (12) ◽  
pp. 120801-120805 ◽  
Author(s):  
Lebao Yang Lebao Yang ◽  
Lifa Hu Lifa Hu ◽  
Dayu Li Dayu Li ◽  
Zhaoliang Cao Zhaoliang Cao ◽  
Quanquan Mu Quanquan Mu ◽  
...  
Keyword(s):  
Field Of View ◽  
Wavefront Sensor ◽  
Wide Field ◽  
Sensor Design ◽  
Multiple Object ◽  
Wide Field Of View

STM studies of crystal growth

1991 ◽  
Vol 49 ◽  
pp. 374-375
Author(s):  
M. G. Lagally
Keyword(s):  
Crystal Growth ◽  
Molecular Beam ◽  
Chemical Vapor ◽  
Sputter Deposition ◽  
Field Of View ◽  
Scanning Tunneling ◽  
Wide Field ◽  
Tunneling Microscopy ◽  
Wide Field Of View ◽  
The One

It has been recognized since the earliest days of crystal growth that kinetic processes of all Kinds control the nature of the growth. As the technology of crystal growth has become ever more refined, with the advent of such atomistic processes as molecular beam epitaxy, chemical vapor deposition, sputter deposition, and plasma enhanced techniques for the creation of “crystals” as little as one or a few atomic layers thick, multilayer structures, and novel materials combinations, the need to understand the mechanisms controlling the growth process is becoming more critical. Unfortunately, available techniques have not lent themselves well to obtaining a truly microscopic picture of such processes. Because of its atomic resolution on the one hand, and the achievable wide field of view on the other (of the order of micrometers) scanning tunneling microscopy (STM) gives us this opportunity. In this talk, we briefly review the types of growth kinetics measurements that can be made using STM. The use of STM for studies of kinetics is one of the more recent applications of what is itself still a very young field.

Sign in / Sign up

Export Citation Format

Share Document