Results 31 to 40 of about 5,982 (227)

Performance Comparison of Wavefront-Sensorless Adaptive Optics Systems by Using of the Focal Plane

International Journal of Optics, 2015
The correction capability and the convergence speed of the wavefront-sensorless adaptive optics (AO) system are compared based on two different system control algorithms, which both use the information of focal plane.
Huizhen Yang, Zhen Zhang, Jian Wu
doaj   +1 more source

Wavefront Distortion Correction for the Non-Uniform-Intensity Light Based on Extreme Learning Machine

IEEE Photonics Journal, 2021
This paper aims to employ a neural network method of extreme learning machine to solve the problem of laser beam cleanup under the dynamic non-uniform-intensity distribution.
Haiqi Lin, Xing He, Shuai Wang, Ping Yang   +3 more
doaj   +1 more source

Wavefront Refraction and Correction [PDF]

Optometry and Vision Science, 2014
Ray, Applegate, David, Atchison, Arthur, Bradley, Adrian, Bruce, Michael, Collins, Jason, Marsack, Scott, Read, Larry N, Thibos, Geunyoung, Yoon   +8 more
  +5 more sources

Enhanced Ultrasound Transmission Through Aberration Layers Using Space‐Coiling Acoustic Metamaterials

Advanced Engineering Materials, EarlyView.
Enhancing ultrasound transmission through an aberration layer exhibiting mismatched impedance with the surrounding medium possesses great implications in imaging and treatment. In this study, we show that a space‐coiling acoustic metamaterial with judiciously tailored structural profile can help improve impedance matching.
Maral Ghanami, Hengzhe Ren, Erqian Dong, Ashkan Ghanbarzadeh‐Dagheyan, Chen Shen   +4 more
wiley   +1 more source

Adaptive wavefront correction in two-photon microscopy using coherence-gated wavefront sensing [PDF]

Proceedings of the National Academy of Sciences, 2006
The image quality of a two-photon microscope is often degraded by wavefront aberrations induced by the specimen. We demonstrate here that resolution and signal size in two-photon microcopy can be substantially improved, even in living biological specimens, by adaptive wavefront correction based on sensing the wavefront of coherence-gated backscattered ...
Rückel, M., Mack-Bucher, J., Denk, W.
openaire   +4 more sources

Chiral Phase Change Nanomaterials

Advanced Functional Materials, EarlyView.
This work demonstrates reversible, non‐volatile phase transitions in chiral Ge2${\rm Ge}_2$Sb2${\rm Sb}_2$Te5${\rm Te}_5$ (GST) nanohelices for high‐speed optical modulation of chirality and dynamic control of the state of polarization (SOP). The chiral nanostructures are fabricated using a highly directional, wafer‐scale physical vapor deposition ...
Joshua A. Burrow, Md Shah Alam, Riad Yahiaoui, Evan M. Smith, Ryan Laing, Jules Gardener, Thomas A. Searles, Piyush J. Shah, Shivashankar Vangala, Joshua R. Hendrickson, Andrew M. Sarangan, Imad Agha   +11 more
wiley   +1 more source

Two‐Photon Grayscale Lithography (2GL) of High Mechanical and Optical Quality 3D Silica Glass Microstructures

Advanced Functional Materials, EarlyView.
Two‐photon grayscale lithography (2GL) enables high‐speed and precise 3D printing of thermolyzed silica glass microstructures with optical‐grade surface quality, high quality factors, and mechanical strength utilizing a custom‐made pre‐glass resist based on polyhedral oligomeric silsesquioxane (POSS) modified with a high‐sensitivity Norrish type II ...
Jonathan L. G. Schneider, Jiajie Liang, Paul Somers, Martin Wegener, Jens Bauer   +4 more
wiley   +1 more source

Wavefront Prediction for Adaptive Optics Without Wavefront Sensing Based on EfficientNetV2-S

Photonics
Adaptive optics (AO) aims to counteract wavefront distortions caused by atmospheric turbulence and inherent system errors. Aberration recovery accuracy and computational speed play crucial roles in its correction capability. To address the issues of slow
Zhiguang Zhang, Zelu Huang, Jiawei Wu, Zhaojun Yan, Xin Li, Chang Liu, Huizhen Yang   +6 more
doaj   +1 more source

Wood‐Derived Nanocellulose‐Biocarbon Fresnel‐Zone Plate Lenses for Sub‐THz Frequency Applications

Advanced Materials Technologies, EarlyView.
Wood‐derived nanocellulose and lignin‐based biocarbon were combined to fabricate fully bio‐based Fresnel zone plate (FZP) lenses for sub‐terahertz frequencies. These sustainable FZP lenses exhibit low dielectric loss and high directivity, achieving performance comparable to that of metallic references, and remain functional under environmental stress ...
Riikka Haataja, Mikko Kokkonen, Niina Halonen, Sami Myllymäki, Umair Rafique, Mandeep Singh, Ossi Laitinen, Heli Jantunen, Kristiina Oksman, Henrikki Liimatainen   +9 more
wiley   +1 more source

In Situ Two‐Dimensional Residual Stress Characterization of Thin Films

Advanced Materials Technologies, EarlyView.
An integrated in situ curvature metrology platform combining speckle‐based curvature optical metrology (SCOM) with multi‐beam optical sensors (MOS) enables spatially resolved two‐dimensional curvature mapping of thick sputtered coatings. The SCOM technique provides excellent agreement with MOS while providing an extended measurable curvature range ...
Wai Jue Tan, Wadwan Singhapong, Arindam Majhi, Chris Bowen, Alexander J.G. Lunt, Hongchang Wang, Kawal Sawhney   +6 more
wiley   +1 more source