Results 51 to 60 of about 2,392,408 (295)
An experimental Rayleigh laser guide star ground layer adaptive optics system for the William Herschel telescope [PDF]
, 2005 The design of an experimental ground layer adaptive optics (GLAO) system that uses a low altitude Rayleigh laser guide star as a wavefront reference source is presented.
Morris, T J, Morris, T. J.
core
Self-Aligning Scanning Shack-Hartmann Sensor for Automatic Wavefront Measurements of High-NA Optics
, 2020 Optical parts, such as lenses or mirrors, are often qualified by surface shape metrology. Wavefront measurements allow for a more direct measurement of the performance of an optical part.
Georg Schitter +7 more
core +1 more source
Advanced Materials Technologies, EarlyView.Direct nanoscratching with a 500 nm diamond lapping film creates groove‐guided liquid‐crystal alignment interfaces on PCB‐compatible Cu‐patterned RF substrates within minutes, eliminating polymer coating and high‐temperature baking. The coating‐free process enables optical/molecular alignment validation and voltage‐programmable 28 GHz reflection‐phase ...
Junseok Ma +5 more
wiley +1 more source
The range of local wavefront curvatures measurable with Shack‐Hartmann wavefront sensors [PDF]
Clinical and Experimental Optometry, 2009 Shack-Hartmann wavefront sensor systems are studied to assess the range of local wavefront curvatures that may be measured for a given choice of lenslet size and focal length and illumination beam characteristics, with special emphasis on systems design for use in wavefront eye refractors.
openaire +2 more sources
Hartmann wavefront measurements at FLASH [PDF]
SPIE Proceedings, 2013 Published by SPIE, Bellingham, Wash.
Keitel, Barbara +8 more
openaire +2 more sources
Group-delay measurement of frequency-converting devices using a comb generator [PDF]
, 2010 We propose a new method for the measurement of (group) delay from the radio-frequency (RF) input to the intermediate-frequency (IF) output of a mixer or a receiver.
Scott, Jonathan B., Hoy, M.
core +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 +9 more
wiley +1 more source
Advancing wavefront sensing: meta Shack-Hartmann sensor enhances phase imaging
Light: Science & ApplicationsA meta-lens array-based Shack-Hartmann wavefront sensor has been developed to break the limits imposed by the size and curvature of traditional micro-lenses, which significantly improves both sampling density and angular resolution of phase measurement ...
Xiaoyuan Liu, Zihan Geng, Mu Ku Chen
doaj +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 +6 more
wiley +1 more source
Wavefront-Constrained Passive Obscured Object Detection
Accurately localizing and segmenting obscured objects from faint light patterns beyond the field of view is highly challenging due to multiple scattering and medium-induced perturbations.
Y Ouyang (13686946) +9 more
core +4 more sources