Minimax Optimization Of Two-Dimensional Cartesian And Fresnel Lens Phased Arrays

1982 ◽  
Author(s):  
R. P. Kraft ◽  
J. F. McDonald
Keyword(s):  
Phased Arrays ◽  
Fresnel Lens ◽  
Two Dimensional ◽  
Minimax Optimization

scholarly journals Rapid Fabrication of Continuous Surface Fresnel Microlens Array by Femtosecond Laser Focal Field Engineering

Micromachines ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 112 ◽  
Author(s):  
Linyu Yan ◽  
Dong Yang ◽  
Qihuang Gong ◽  
Yan Li
Keyword(s):  
Femtosecond Laser ◽  
Three Dimensional ◽  
Fresnel Lens ◽  
Two Dimensional ◽  
Direct Writing ◽  
Lens Array ◽  
Two Photon ◽  
Rapid Fabrication ◽  
Continuous Surface ◽  
Two Photon Polymerization

Femtosecond laser direct writing through two-photon polymerization has been widely used in precision fabrication of three-dimensional microstructures but is usually time consuming. In this article, we report the rapid fabrication of continuous surface Fresnel lens array through femtosecond laser three-dimensional focal field engineering. Each Fresnel lens is formed by continuous two-photon polymerization of the two-dimensional slices of the whole structure with one-dimensional scan of the corresponding two-dimensional engineered intensity distribution. Moreover, we anneal the lens array to improve its focusing and imaging performance.

Two-Dimensional Mapping of Localized Characteristics of Concentrator Photovoltaic Module

2012 ◽  
Vol 725 ◽  
pp. 187-190
Author(s):  
Hiroto Yano ◽  
Hirokazu Nagai ◽  
Kazuyuki Tamura ◽  
Kenji Araki ◽  
Kensuke Nishioka
Keyword(s):  
High Efficiency ◽  
Tracking Error ◽  
Fresnel Lens ◽  
Optical Systems ◽  
Photovoltaic Module ◽  
Two Dimensional ◽  
Solar Simulator ◽  
Tracking Errors ◽  
Irradiation Angle ◽  
Dimensional Mapping

For the development of concentrator photovoltaic (CPV) module realizing high efficiency, it is necessary to achieve the high efficiency optical system including Fresnel lens and homogenizer. For the improvement of optical systems, it is very important to understand the contribution of the light irradiated to a localized position on the Fresnel lens. The light beam induced current (LBIC) system was constructed to evaluate the focusing characteristic of the CPV module. We locally irradiated a light from solar simulator to the CPV mini-module and measured the generation current, and the localized characteristics were represented by two-dimensional mappings. Moreover, we evaluated the influence of tracking error by changing the irradiation angle. In the case of tracking errors, the peak of generated current was shifted and the current was decreased. In the case of tracking error of 1.0 o, the total generated current was reduced 12%, in comparison with the normal irradiance.

Two-dimensional apodized silicon photonic phased arrays

2014 ◽  
Vol 39 (2) ◽  
pp. 367 ◽  
Author(s):  
Jie Sun ◽  
Ehsan shah Hosseini ◽  
Ami Yaacobi ◽  
David B. Cole ◽  
Gerald Leake ◽  
...  
Keyword(s):  
Phased Arrays ◽  
Two Dimensional ◽  
Silicon Photonic

scholarly journals Remote, Volumetric Ultrasonic Imaging of Defects Using Two-Dimensional Laser Induced Phased Arrays

2021 ◽  
Author(s):  
Peter Lukacs ◽  
Geo Davis ◽  
Theodosia Stratoudaki ◽  
Yashar Javadi ◽  
Gareth Pierce ◽  
...  
Keyword(s):  
Phased Arrays ◽  
Extreme Environments ◽  
Three Dimensional ◽  
Fe Model ◽  
Two Dimensional ◽  
Destructive Testing ◽  
Cross Sectional ◽  
Volumetric Images ◽  
Different Depths ◽  
Non Destructive

Abstract Manufacturing processes, such as welding and additive manufacturing, take place at high temperatures and extreme environments that offer significant challenges to conventional non-destructive testing methods. Laser Induced Phased Arrays (LIPAs) have evolved as a promising testing method for the aforesaid applications due to its remote and couplant free operation. Contrary to transducer-based phased arrays, LIPAs are synthesized in post-processing by scanning the generation and detection lasers. The data from one-dimensional (1D) phased arrays are used to produce two-dimensional (2D), cross-sectional images, whereas the data from two-dimensional phased arrays generate three-dimensional (3D) images, thus providing more information on defect characterization. In this work, two-dimensional (2D) LIPAs are synthesized in the non-destructive thermoelastic regime using lasers for ultrasonic generation and detection, in order to image defects at different depths inside an aluminum sample. The acquired data is processed using the Total Focusing Method (TFM) algorithm to obtain volumetric images representing the interior of the sample. A 3D finite element (FE) model is also developed to support the experiments.

Heating of biological tissues by two-dimensional phased arrays with random and regular element distributions

2004 ◽  
Vol 50 (2) ◽  
pp. 222-231 ◽  
Author(s):  
E. A. Filonenko ◽  
L. R. Gavrilov ◽  
V. A. Khokhlova ◽  
J. W. Hand
Keyword(s):  
Regular Element ◽  
Phased Arrays ◽  
Biological Tissues ◽  
Two Dimensional
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