Results 31 to 40 of about 43,714 (202)

Wavefront Derived Refraction and Full Eye Biometry in Pseudophakic Eyes. [PDF]

PLoS ONE, 2016
To assess wavefront derived refraction and full eye biometry including ciliary muscle dimension and full eye axial geometry in pseudophakic eyes using spectral domain OCT equipped with a Shack-Hartmann wavefront sensor.Twenty-eight adult subjects (32 ...
Xinjie Mao, James T Banta, Bilian Ke, Hong Jiang, Jichang He, Che Liu, Jianhua Wang   +6 more
doaj   +1 more source

Substrate Reshaping for Optically Tuned Liquid‐Printed Microlenses Beyond Their Wetting Properties

Advanced Materials Technologies, Volume 8, Issue 19, October 10, 2023., 2023
Print‐n‐release, a strategy for microlens fabrication with tuned focusing performance is presented. Based on printing prepolymer microdroplets on top of mechanically stretched elastomeric substrates, print‐n‐release allows for the decoupling of the final microlens shape from the wetting behavior between prepolymer and substrate.
Ernest Martí Jerez, J. Marcos Fernández Pradas, Pere Serra, Martí Duocastella   +3 more
wiley   +1 more source

Expanded Scene Image Preprocessing Method for the Shack–Hartmann Wavefront Sensor

Applied Sciences, 2023
Due to the influence of atmospheric turbulence, the detector, and background noise, the subaperture image of an extended scene Shack–Hartmann wavefront sensor will have a low signal-to-noise ratio, which will introduce errors to the offset estimation and
Bo Chen, Jingjing Jia, Yilin Zhou, Yirui Zhang, Zhaoyi Li   +4 more
doaj   +1 more source

Scientific detector workshop 2022 on‐sky performance verification of near‐infrared e−APD technology for wavefront sensing and demonstration of e−APD pixel performance to improve the sensitivity of large science focal planes

Astronomische Nachrichten, Volume 344, Issue 8-9, October-November 2023., 2023
Abstract Near‐infrared adaptive optics as well as fringe tracking for coherent beam combination in optical interferometry require the development of high‐speed sensors. Because of the high speed, a large analog bandwidth is required. The short exposure times result in small signal levels which require noiseless detection.
Gert Finger, Frank Eisenhauer, Reinhard Genzel, Christopher Mandla, Ian Baker, Domingo Alvarez, Antonio Amorim, Wolfgang Brandner, Christophe Dupuy, Casey Deen, Derek Ives, Leander Mehrgan, Manfred Meyer, Karin Perraut, Guy Perrin, Jörg Stegmeier, Christian Straubmeier, Harald J. Weller, Vincent Isgar   +18 more
wiley   +1 more source

Modified Method to Detect the Turbulent Layers in the Atmospheric Boundary Layer for the Large Solar Vacuum Telescope

Atmosphere, 2021
A method to detect the atmospheric turbulent layers using a single Shack–Hartmann wavefront sensor is discussed. In order to determine the height distribution of the atmospheric turbulence above a telescope, we register the wavefront distortions at ...
Artem Yurievich Shikhovtsev, Pavel Gavrilovich Kovadlo, Alexander Victorovich Kiselev, Dmitriy Yurievich Kolobov, Vladimir Petrovich Lukin, Ivan Victorovich Russkikh, Maxim Yurievich Shikhovtsev   +6 more
doaj   +1 more source

New opportunities for astronomical imaging systems

Astronomische Nachrichten, Volume 344, Issue 8-9, October-November 2023., 2023
Abstract This paper will look at two significant technological developments, one concerning the performance of optical and infrared detector systems, which are now capable of genuine photon counting performance, and secondly a new approach to tackling the problem of adaptive optics when only faint reference stars are available close to the target ...
Craig Mackay
wiley   +1 more source

Surface Measurement Using Compressed Wavefront Sensing

Photonic Sensors, 2018
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, Ningqun Guo, Edwin Chong, Xin Wang   +3 more
doaj   +1 more source

Highly Stable Spatio-Temporal Prediction Network of Wavefront Sensor Slopes in Adaptive Optics

Sensors, 2023
Adaptive Optics (AO) technology is an effective means to compensate for wavefront distortion, but its inherent delay error will cause the compensation wavefront on the deformable mirror (DM) to lag behind the changes in the distorted wavefront ...
Ning Wang, Licheng Zhu, Qiang Yuan, Xinlan Ge, Zeyu Gao, Shuai Wang, Ping Yang   +6 more
doaj   +1 more source

Integrated coronagraphy and wavefront sensing with the PIAACMC [PDF]

, 2023
Uncorrected wavefront errors create speckle noise in high-contrast observations at small inner-working angles. These speckles can be sensed and controlled by using coronagraph integrated wavefront sensors. Here, we will present how the Phase Induced Amplitude Apodized Complex Mask Corongraph (PIAACMC) can be integrated with both a Self-Coherent Camera (
arxiv   +1 more source

Study of a MEMS-based Shack-Hartmann wavefront sensor with adjustable pupil sampling for astronomical adaptive optics [PDF]

, 2008
We introduce a Shack-Hartmann wavefront sensor for adaptive optics that enables dynamic control of the spatial sampling of an incoming wavefront using a segmented mirror microelectrical mechanical systems (MEMS) device.
Baranec, Christoph, Dekany, Richard
core   +1 more source