Three-Dimensional Gradient-Index Materials and Their Applications in Microwave Lens Antennas

2013 ◽  
Vol 61 (5) ◽  
pp. 2561-2569 ◽  
Author(s):  
Hui Feng Ma ◽  
Ben Geng Cai ◽  
Teng Xiang Zhang ◽  
Yan Yang ◽  
Jiang ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Gradient Index ◽  
Lens Antennas

Three-Dimensional Spatial Image Forming Using Gradient-Index Lens Arrays.

2002 ◽  
Vol 30 (12) ◽  
pp. 731-736
Author(s):  
Fumio OKANO ◽  
Jun ARAI ◽  
Makoto OKUI
Keyword(s):  
Three Dimensional ◽  
Gradient Index ◽  
Spatial Image ◽  
Gradient Index Lens

scholarly journals Enhanced control of light and sound trajectories with three-dimensional gradient index lenses

2012 ◽  
Vol 14 (3) ◽  
pp. 035011 ◽  
Author(s):  
T M Chang ◽  
G Dupont ◽  
S Enoch ◽  
S Guenneau
Keyword(s):  
Three Dimensional ◽  
Gradient Index

Alumina-Doped Silica Gradient-Index (GRIN) Lenses by Slurry-Based Three-Dimensional Printing (S-3DP™)

2002 ◽  
Vol 758 ◽  
Author(s):  
Hong-Ren Wang ◽  
Michael J. Cima ◽  
Emanuel M. Sachs
Keyword(s):  
Complex Structure ◽  
Three Dimensional ◽  
Optical Quality ◽  
Vacuum Furnace ◽  
Gradient Index ◽  
Alumina Concentration ◽  
Graded Materials ◽  
Three Dimensional Printing ◽  
Dimensional Printing

ABSTRACTThe traditional Slurry-based Three-dimensional Printing (S-3DP™) process has been used to fabricate complex structure materials by printing organic binders in selected positions on each printing layer. This process is modified to fabricate functional graded materials, such as gradient index (GRIN) lenses, by depositing different concentrations of dopant at different positions. The modified S-3DP™ process offers advantages over conventional GRIN lens processes, including reduced processing time, improved compositional flexibility, and increased index profile dimensionality. Two different approximately parabolic dopant concentration profiles, which have maximum alumina concentrations of 1.63 mol% and 2.50 mol%, are printed into silica powder beds using S-3DP™. The samples with maximum alumina concentration of 1.63 mol% have been sintered into optical transparency at 1650 0C for 30 minutes in a vacuum furnace (5×10-6 torr) while an additional dehydration process before sintering was required for the samples with maximum alumina concentration of 2.50 mol%. The magnifying effects of GRIN lenses with profiles of 1.63 mol% and 2.50 mol% alumina were observed, yielding effective focal lengths of 10 cm and 6.1 cm, respectively. Light diffraction, which results from the locally inhomogeneous dopant distribution and reduces the optical quality of GRIN lenses, was also observed.

scholarly journals Ray-tracing simulations of liquid-crystal gradient-index lenses for three-dimensional displays

2009 ◽  
Vol 26 (11) ◽  
pp. 2035 ◽  
Author(s):  
Maarten Sluijter ◽  
Angie Herzog ◽  
Dick K. G. de Boer ◽  
Marcel P. C. M. Krijn ◽  
H. Paul Urbach
Keyword(s):  
Liquid Crystal ◽  
Ray Tracing ◽  
Three Dimensional ◽  
Gradient Index

Three-dimensional vibration of rotating functionally graded beams

2017 ◽  
Vol 24 (15) ◽  
pp. 3292-3306 ◽  
Author(s):  
Jianshi Fang ◽  
Ding Zhou ◽  
Yun Dong
Keyword(s):  
Chebyshev Polynomials ◽  
Ritz Method ◽  
Three Dimensional ◽  
Functionally Graded ◽  
Gradient Index ◽  
Coupling Dynamic ◽  
Cantilevered Beams ◽  
Stiffening Effect ◽  
Large Deformation Problems ◽  
Space Method

The three-dimensional free vibration and time response of rotating functionally graded (FG) cantilevered beams are studied. Material properties of functionally graded beams are assumed to change gradually through both the width and the thickness in power-law form. The second-kind Lagrange’s equations are used in conjunction with the Ritz method to derive the comprehensive coupling dynamic equations for the axial, chordwise, and flapwise motions. The trial functions of deformations are taken as the products of the Chebyshev polynomials and the corresponding boundary functions. Nonlinear coupling deformations are considered to capture the dynamic stiffening effect due to the rotating motion. The influences of the material gradient index and rotational speed on modal characteristics are investigated by the state space method. The eigenvalue loci veering phenomena with modal conversions are exhibited. The time responses indicate that the deformations of rotating functionally graded beams are greatly affected by the material gradient index. It is shown that for large deformation problems, using Chebyshev polynomials is more efficient in computing precision and robustness than using other polynomials.

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