Results 31 to 40 of about 95,373 (320)
Wavefront sensing with critical sampling [PDF]
Different types of nonredundant sampling patterns are shown to guarantee completeness of the basis formed by the sampled partial derivatives of Zernike polynomials, commonly used to reconstruct the wavefront from its slopes (wavefront sensing). In the ideal noise-free case, this enables one to recover double the number of modes J than sampling points I
Navarro, Rafael+2 more
openaire +4 more sources
Near-infrared wavefront sensing [PDF]
We discuss the advantages of wavefront sensing at near-infrared (IR) wavelengths with low-noise detector technologies that have recently become available. In this paper, we consider low order sensing with laser guide star (LGS) adaptive optics (AO) and high order sensing with natural guide star (NGS) AO.
Wizinowich, Peter+10 more
openaire +5 more sources
Calibrating a high-resolution wavefront corrector with a static focal-plane camera
We present a method to calibrate a high-resolution wavefront-correcting device with a single, static camera, located in the focal plane; no moving of any component is needed.
Codona, Johanan+5 more
core +6 more sources
Surface Measurement Using Compressed Wavefront Sensing
Compressed sensing leverages the sparsity of signals to reduce the amount of measurements required for its reconstruction. The Shack-Hartmann wavefront sensor meanwhile is a flexible sensor where its sensitivity and dynamic range can be adjusted based on
Eddy Mun Tik Chow+3 more
doaj +1 more source
The Asymmetric Pupil Fourier Wavefront Sensor [PDF]
This paper introduces a novel wavefront sensing approach that relies on the Fourier analysis of a single conventional direct image. In the high Strehl ratio regime, the relation between the phase measured in the Fourier plane and the wavefront errors in ...
Martinache, Frantz
core +2 more sources
A Tip–Tilt and Piston Detection Approach for Segmented Telescopes
Accurate segmented mirror wavefront sensing and control is essential for next-generation large aperture telescope system design. In this paper, a direct tip–tilt and piston error detection technique based on model-based phase retrieval with multiple ...
Shun Qin, Wai Kin Chan
doaj +1 more source
Shack–Hartmann Wavefront Sensing Based on Four-Quadrant Binary Phase Modulation
Aiming at the problem that it is difficult for the conventional Shack–Hartmann wavefront sensor to achieve high-precision wavefront reconstruction with low spatial sampling, a kind of Shack–Hartmann wavefront sensing technology based on four-quadrant ...
Mengmeng Zhao+7 more
doaj +1 more source
Digging Deeper through Biological Specimens Using Adaptive Optics-Based Optical Microscopy
Optical microscopy is a vital tool for visualizing the cellular and sub-cellular structures of biological specimens. However, due to its limited penetration depth, its biological applicability has been hindered.
Gagan Raju, Nirmal Mazumder
doaj +1 more source
Closed-loop focal plane wavefront control with the SCExAO instrument [PDF]
This article describes the implementation of a focal plane based wavefront control loop on the high-contrast imaging instrument SCExAO (Subaru Coronagraphic Extreme Adaptive Optics).
Guyon, Olivier+2 more
core +4 more sources
Single conjugate adaptive optics for the ELT instrument METIS [PDF]
The ELT is a 39m large, ground-based optical and near- to mid-infrared telescope under construction in the Chilean Atacama desert. Operation is planned to start around the middle of the next decade.
Absil, Olivier+9 more
core +3 more sources