scholarly journals SOWAT: High-resolution imaging with only partial AO correction

2019 ◽  
Vol 14 (S351) ◽  
pp. 185-188
Author(s):  
Felix Bosco ◽  
Jörg-Uwe Pott ◽  
Rainer Schödel
Keyword(s):  
Adaptive Optics ◽  
Globular Clusters ◽  
Reconstruction Algorithms ◽  
Optical Aberrations ◽  
Point Spread Functions ◽  
Point Spread ◽  
Resolution Imaging ◽  
Image Reconstruction Algorithms ◽  
Discrete Integration ◽  
Atmospheric Seeing

AbstractObservations of dense stellar systems such as globular clusters (GCs) are limited in resolution by the optical aberrations induced by atmospheric turbulence (atmospheric seeing). At the example of holographic speckle imaging, we now study, to which degree image reconstruction algorithms are able to remove residual aberrations from a partial adaptive optics (AO) correction, such as delivered from ground-layer AO (GLAO) systems. Simultaneously, we study, how such algorithms benefit from being applied to pre-corrected instead of natural point-spread functions (PSFs). We find that using partial AO corrections already lowers the demands on the holography reference star by ∼3 mag, what makes more fields accessible for this technique, and also that the discrete integration times may be chosen about 2–3× longer, since the effective wavefront evolution is slowed down by removing the perturbation power.

Maximally Informative Point Spread Functions for 3D Super-Resolution Imaging

CLEO: 2015 ◽  
2015 ◽  
Author(s):  
Yoav Shechtman ◽  
Steffen J. Sahl ◽  
Adam S. Backer ◽  
W. E. Moerner
Keyword(s):  
Super Resolution ◽  
Point Spread Functions ◽  
Point Spread ◽  
Resolution Imaging

scholarly journals Synthesis of Super-Oscillatory Point-Spread Functions with Taylor-Like Tapered Sidelobes for Advanced Optical Super-Resolution Imaging

Photonics ◽  
2021 ◽  
Vol 8 (3) ◽  
pp. 64
Author(s):  
Haitang Yang ◽  
George V. Eleftheriades
Keyword(s):  
Spatial Light Modulator ◽  
Super Resolution ◽  
Sidelobe Level ◽  
Light Modulator ◽  
Point Spread Functions ◽  
Antenna Theory ◽  
Point Spread ◽  
Oscillation Phenomenon ◽  
Resolution Imaging ◽  
Directive Antenna

Recently, the super-oscillation phenomenon has attracted attention because of its ability to super-resolve unlabelled objects in the far-field. Previous synthesis of super-oscillatory point-spread functions used the Chebyshev patterns where all sidelobes are equal. In this work, an approach is introduced to generate super-oscillatory Taylor-like point-spread functions that have tapered sidelobes. The proposed method is based on the Schelkunoff’s super-directive antenna theory. This approach enables the super-resolution, the first sidelobe level and the tapering rate of the sidelobes to be controlled. Finally, we present the design of several imaging experiments using a spatial light modulator as an advanced programmable grating to form the Taylor-like super-oscillatory point-spread functions and demonstrate their superiority over the Chebyshev ones in resolving the objects of two apertures and of a mask with the letter E.

scholarly journals Tiny grains shining bright in the gaps of Herbig Ae transitional discs

2019 ◽  
Vol 486 (3) ◽  
pp. 3721-3740 ◽  
Author(s):  
Eloise K Birchall ◽  
Michael J Ireland ◽  
Christoph Federrath ◽  
John D Monnier ◽  
Stefan Kraus ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Adaptive Optics ◽  
Surface Density ◽  
Forward Modelling ◽  
Point Spread Functions ◽  
Density Distributions ◽  
Disc Surface ◽  
Point Spread ◽  
Adaptive Optics Imaging ◽  
Modelling Approach

ABSTRACT This work presents a study of two Herbig Ae transitional discs, Oph IRS 48 and HD 169142; which both have reported rings in their dust density distributions. We use Keck-II/NIRC2 adaptive optics imaging observations in the L′ filter (3.8 $\mu$m) to probe the regions of these discs inwards of ${\sim }20\, \mathrm{au}$ from the star. We introduce our method for investigating these transitional discs, which takes a forward modelling approach: making a model of the disc (using the Monte Carlo radiative transfer code radmc3d), convolving it with point spread functions of calibrator stars, and comparing the convolved models with the observational data. The disc surface density parameters are explored with a Monte Carlo Markov Chain technique. Our analysis recovers emission from both of the discs interior to the well-known optically thick walls, modelled as a ring of emission at ${\sim }15\, \mathrm{au}$ in Oph IRS 48, and ${\sim }7\, \mathrm{au}$ for HD 169142, and identifies asymmetries in both discs. Given the brightness of the near-symmetric rings compared to the reported companion candidates, we suggest that the reported companion candidates can be interpreted as slightly asymmetric disc emission or illumination.

scholarly journals A Full-Aperture Image Synthesis Method for the Rotating Rectangular Aperture System Using Fourier Spectrum Restoration

Photonics ◽  
2021 ◽  
Vol 8 (11) ◽  
pp. 522
Author(s):  
Guomian Lv ◽  
Hao Xu ◽  
Huajun Feng ◽  
Zhihai Xu ◽  
Hao Zhou ◽  
...  
Keyword(s):  
Fourier Spectrum ◽  
Synthesis Method ◽  
Image Synthesis ◽  
Objective Evaluation ◽  
The Novel ◽  
Point Spread Functions ◽  
Synthesis Algorithm ◽  
Rectangular Aperture ◽  
Point Spread ◽  
Resolution Imaging

The novel rotating rectangular aperture (RRA) system provides a good solution for space-based, large-aperture, high-resolution imaging tasks. Its imaging quality depends largely on the image synthesis algorithm, and the mainstream multi-frame deblurring approach is sophisticated and time-consuming. In this paper, we propose a novel full-aperture image synthesis algorithm for the RRA system, based on Fourier spectrum restoration. First, a numerical simulation model is established to analyze the RRA system’s characteristics and obtain the point spread functions (PSFs) rapidly. Then, each image is used iteratively to calculate the increment size and update the final restored Fourier spectrum. Both the simulation’s results and the practical experiment’s results show that our algorithm performs well in terms of objective evaluation and time consumption.

scholarly journals Turbulent and adaptive optics corrected point-spread functions as convolutive orders of the phase power spectral density

2018 ◽  
Vol 481 (4) ◽  
pp. 5210-5215 ◽  
Author(s):  
Romain J L Fétick ◽  
Benoit Neichel ◽  
Laurent M Mugnier ◽  
Aurélie Montmerle-Bonnefois ◽  
Thierry Fusco
Keyword(s):  
Spectral Density ◽  
Power Spectral Density ◽  
Adaptive Optics ◽  
Point Spread Functions ◽  
Point Spread ◽  
Power Spectral

Comparison of image reconstruction algorithms using adaptive optics instrumentation

1998 ◽  
Author(s):  
David W. Tyler ◽  
Stephen D. Ford ◽  
Bobby R. Hunt ◽  
Richard G. Paxman ◽  
Michael C. Roggemann ◽  
...  
Keyword(s):  
Image Reconstruction ◽  
Adaptive Optics ◽  
Reconstruction Algorithms ◽  
Image Reconstruction Algorithms

scholarly journals Numerically enhanced adaptive optics-based 3D STED microscopy for deep-tissue super-resolved imaging

2019 ◽  
Author(s):  
Piotr Zdankowski ◽  
Maciej Trusiak ◽  
David McGloin ◽  
Jason R. Swedlow
Keyword(s):  
Adaptive Optics ◽  
Signal To Noise Ratio ◽  
Super Resolution ◽  
Thick Layer ◽  
Block Matching ◽  
Stimulated Emission ◽  
Optical Aberrations ◽  
Deep Tissue ◽  
Resolution Imaging ◽  
Induced Pluripotent

AbstractIn stimulated emission depletion (STED) nanoscopy, the major origin of decreased signal-to-noise ratio within images can be attributed to sample photobleaching and strong optical aberrations. This is due to STED utilising both a high power depletion laser (increasing risk of photodamage), while the depletion beam is very sensitive to sample-induced aberrations. Here we demonstrate a custom-built 3D STED microscope with automated aberration correction that is capable of 3D super-resolution imaging through thick, highly aberrating, tissue. We introduce and investigate image denoising by block-matching and collaborative filtering (BM3D) to numerically enhance fine object details otherwise mixed with noise. Numerical denoising provides an increase in the final effective resolution of the STED imaging of 31% using the well-established Fourier ring correlation metric. Experimental validation of the proposed method is achieved through super-resolved 3D imaging of axons in differentiated induced pluripotent stem cells growing under a 80µm thick layer of tissue with lateral and axial resolution of 256nm and 300nm, respectively.

Design of Double-helix Point Spread Functions for 3D Super-resolution Imaging

2012 ◽  
Author(s):  
Ginni Grover ◽  
Keith DeLuca ◽  
Sean Quirin ◽  
Jennifer DeLuca ◽  
Rafael Piestun
Keyword(s):  
Double Helix ◽  
Super Resolution ◽  
Point Spread Functions ◽  
Point Spread ◽  
Resolution Imaging
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