Results 21 to 30 of about 4,473,381 (352)

Large Piston Error Detection Method Based on the Multiwavelength Phase Shift Interference and Dynamic Adjustment Strategy

Photonics, 2022
As the loading space in rockets and mirror fabrication technology is limited, optical systems in space cannot have large optical apertures. However, the successful launch and excellent performance of the James Webb Telescope indicate that segmented ...
Rongjie Qin, Zihao Yin, Youlong Ke, Yinnian Liu   +3 more
doaj   +1 more source

Fast High-Resolution Phase Diversity Wavefront Sensing with L-BFGS Algorithm

Sensors, 2023
The presence of manufacture error in large mirrors introduces high-order aberrations, which can severely influence the intensity distribution of point spread function.
Haoyuan Zhang, Guohao Ju, Liang Guo, Boqian Xu, Xiaoquan Bai, Fengyi Jiang, Shuyan Xu   +6 more
doaj   +1 more source

Active Support System for the Correction of a 4m SiC Primary Mirror Based on the Bending Mode

Applied Sciences, 2023
Active optics is a key technology in ground-based large-aperture telescopes. The active correction of the surface shape of the primary mirror is used to reduce the surface shape error and improve the imaging quality.
Zhiyuan Yu, Xiaoxia Wu, Fuguo Wang
doaj   +1 more source

Design and Parameter Identification for a Positioning Platform with a Large Stroke and High Precision for Segmented Mirrors

Micromachines, 2023
An active optical system with three segmented mirrors was proposed to verify the co-focus and co-phase progress. In this system, a kind of large-stroke and high-precision parallel positioning platform was specially developed to help support the mirrors ...
Zihao Yin, Rongjie Qin, Haoting Du, Weiyinuo Zhou, Jialin Sun, Dexin Sun, Yinnian Liu   +6 more
doaj   +1 more source

In-Situ Metrology of Large Segmented Detector Based on Modified Optical Truss

IEEE Photonics Journal, 2023
To precisely map cosmic structures and capture time-domain events, future large survey telescopes will be equipped with segmented detectors that greatly expand their field of view. Segment flatness and assembly accuracy will be essential for them to make
Qichang An, Hanfu Zhang, Xiaoxia Wu, Jianli Wang, Tao Chen, Jingxu Zhang, Hongwen Li   +6 more
doaj   +1 more source

Active Optics—Advances of Cycloid-like Variable Curvature Mirrors for the VLTI Array

Photonics, 2022
Elasticity theory and active optics led us to the discovery of three geometrical configurations of variable curvature mirrors (VCMs) that are either cycloid-like or tulip-like thickness distributions. Cycloid-like VCMs are generated by a uniform load—air
Gerard Rene Lemaitre, Pascal Vola, Patrick Lanzoni, Silvio Mazzanti, Frederic J. Dérie, Frederic Y. Gonté   +5 more
doaj   +1 more source

Active Optics–Freeform Segment Mirror Replications from a Deformable Matrix

Photonics, 2022
We present a new active optics method for making smooth aspheric, or freeform, mirrors by replication technique from an elastically deformable matrix.
Gerard R. Lemaitre, Patrick Lanzoni
doaj   +1 more source

Extending Capture Range for Piston Error in Segmented Primary Mirror Telescopes Based on Wavelet Support Vector Machine With Improved Particle Swarm Optimization

IEEE Access, 2020
In the co-phasing techniques applied to the segmented telescope, a Shack-Hartmann wavefront sensor cannot accurately detect the piston error of the segment. Although the phase diversity (PD) algorithm can detect the piston error of each segment, it fails
Haifeng Cao, Jingxu Zhang, Fei Yang, Qichang An, Ye Wang   +4 more
doaj   +1 more source

Recent Developments in UV Optics for Ultra-Short, Ultra-Intense Coherent Light Sources

Photonics, 2015
With the advent of Free Electron Lasers and general UV ultra-short, ultra-intense sources, optics needed to transport such radiation have evolved significantly to standard UV optics.
Daniele Cocco
doaj   +1 more source

Hierarchical Morphing Control of an Ultra-Lightweight Electro-Actuated Polymer Telescope with Thin-Film Actuators

Micromachines, 2023
This paper explores advanced shape control techniques for ultra-lightweight electro-actuated polymers with composite ferroelectric thin films. It begins with an overview of PVDF-TrFE film actuators used in the development of thin-shell composites ...
Kainan Wang, Yuxuan Gong, Yian Yu, André Preumont   +3 more
doaj   +1 more source