Results 21 to 30 of about 5,509 (162)

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

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

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

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

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

Impact of CMOS Pixel and Electronic Circuitry in the Performance of a Hartmann-Shack Wavefront Sensor

Sensors, 2018
This work presents a numerical simulation of a Hartmann-Shack wavefront sensor (WFS) that assesses the impact of integrated electronic circuitry on the sensor performance, by evaluating a full detection chain encompassing wavefront sampling ...
Úrsula Vasconcelos Abecassis, Davies William de Lima Monteiro, Luciana Pedrosa Salles, Carlos Augusto de Moraes Cruz, Pablo Nunes Agra Belmonte   +4 more
doaj   +1 more source

Atmospheric Turbulence with Kolmogorov Spectra: Software Simulation, Real-Time Reconstruction and Compensation by Means of Adaptive Optical System with Bimorph and Stacked-Actuator Deformable Mirrors

Photonics, 2023
Atmospheric turbulence causes refractive index fluctuations, which in turn introduce extra distortions to the wavefront of the propagated radiation. It ultimately degrades telescope resolution (in imaging applications) and reduces radiation power density
Ilya Galaktionov, Julia Sheldakova, Vadim Samarkin, Vladimir Toporovsky, Alexis Kudryashov   +4 more
doaj   +1 more source

Multiple guide star tomography demonstration at Palomar observatory [PDF]

, 2006
We have built and field tested a multiple guide star tomograph with four Shack-Hartmann wavefront sensors. We predict the wavefront on the fourth sensor channel estimated using wavefront information from the other three channels using synchronously ...
Britton, M. C., Dekany, R. G., Flicker, R. C., Hickey, J., Platt, B. C., Roberts, J. E., Shelton, J. C., Troy, M., Velur, V.   +8 more
core   +1 more source

Wide-Aperture Bimorph Deformable Mirror for Beam Focusing in 4.2 PW Ti:Sa Laser

Applied Sciences, 2022
The bimorph deformable mirror with a diameter of 320 mm, including 127 control electrodes, has been developed and tested. The flatness of the initial mirror surface of about 1 μm (P-V) was achieved by mechanically adjusting the mirror substrate fixed in ...
Vadim Samarkin, Alexander Alexandrov, Ilya Galaktionov, Alexis Kudryashov, Alexander Nikitin, Alexey Rukosuev, Vladimir Toporovsky, Julia Sheldakova   +7 more
doaj   +1 more source

Simplifying the detection of optical distortions by machine learning [PDF]

Journal of Innovative Optical Health Sciences, 2020
Adaptive optics has been widely used in biological science to recover high-resolution optical image deep into the tissue, where optical distortion detection with high speed and accuracy is strongly required.
Shuwen Hu, Lejia Hu, Biwei Zhang, Wei Gong, Ke Si   +4 more
doaj   +1 more source