Two- and three-Dimensional Refractive Index Lattices Formed by Laterally Patterned Porous Silicon Layers

1999 ◽  
Vol 597 ◽  
Author(s):  
S. Uehara ◽  
H. Sasabu ◽  
K Taira ◽  
T. Hashimoto ◽  
T. Matsubara
Keyword(s):  
Refractive Index ◽  
Porous Silicon ◽  
Three Dimensional ◽  
Index Structure ◽  
Two Dimensional ◽  
Cladding Layer ◽  
Anodization Process ◽  
N Doping ◽  
Index Contrast ◽  
P Type

AbstractPorous silicon was used to fabricate refractive index lattices. Patterned n-doping and/ or substrate etching were used to introduce lateral periodicity. By anodizing p-type substrate with an n-doped area, we realized large refractive index contrast two-dimensional lattices with underlying cladding layer. The anodization process showed an effect specific to the small dimensional patterning and this effect has significant influence on the formed refractive index structure.

Resonant modal analysis and dual-mode tailoring in high refractive index contrast two-dimensional nanorod arrays

Optik ◽  
2019 ◽  
Vol 181 ◽  
pp. 231-238
Author(s):  
Jianyu Zhou ◽  
Tian Sang ◽  
Junlang Li ◽  
La Wang ◽  
Rui Wang ◽  
...  
Keyword(s):  
Refractive Index ◽  
Modal Analysis ◽  
High Refractive Index ◽  
Two Dimensional ◽  
Nanorod Arrays ◽  
Dual Mode ◽  
Refractive Index Contrast ◽  
Index Contrast

scholarly journals Design of highly-efficient acoustic waveguide couplers using impedance-tunable transformation acoustics

2020 ◽  
Vol 34 (32) ◽  
pp. 2050250
Author(s):  
Jun Cao ◽  
Fenghua Qi ◽  
Senlin Yan ◽  
Lifa Zhang
Keyword(s):  
Refractive Index ◽  
Impedance Matching ◽  
Coupling Efficiency ◽  
Three Dimensional ◽  
Two Dimensional ◽  
Low Frequencies ◽  
Acoustic Waveguide ◽  
Acoustic Coupling ◽  
Transformation Medium ◽  
Transformation Acoustics

In this paper, the theory of impedance-tunable transformation acoustics in the geometric-acoustics limit is proposed to design efficient two-dimensional acoustic waveguide couplers. By choosing suitable impedance functions in the original space, impedance matching between the transformation medium and the background medium becomes possible, and the reflection at the boundary is reduced. The theory can be used to enable efficient acoustic coupling between waveguides of different sizes and different embedded media. By selecting an appropriate impedance function and a tunable acoustic refractive index, the transformed medium in the coupler can become a simplified parameter medium, for which the bulk modulus is a constant. This makes the experiment substantially easier. The problem of a reduced coupling-efficiency at low frequencies (a deviation from the geometric acoustic approximation) can be mitigated by selecting a large acoustic refractive index. Our two-dimensional numerical simulations indicate that this theoretical design works very well. The method can be extended to other transformation acoustic designs including three-dimensional cases.

Exploring the Ruddlesden−Popper Layered Organic-Inorganic Hybrid Semiconducting Perovskite for Visible-Blind Ultraviolet Photodetection

CrystEngComm ◽  
2021 ◽  
Author(s):  
Yuyin Wang ◽  
Bin Su ◽  
Guoming Lin ◽  
Huiru Lou ◽  
Shouxin Wang ◽  
...  
Keyword(s):  
Physical Properties ◽  
Three Dimensional ◽  
Metal Halide ◽  
Two Dimensional ◽  
Inorganic Hybrid ◽  
Perovskite Materials ◽  
Halide Perovskites ◽  
P Type ◽  
Visible Blind

Compared to the three-dimensional (3D) perovskite materials, the Ruddlesden−Popper (R-P) type two-dimensional (2D) organic-inorganic metal halide perovskites have indicated specific unique physical properties that include moisture-stable behaviours, exciton effects, and...

Low refractive index contrast porous silicon omnidirectional reflectors

2009 ◽  
Vol 95 (1) ◽  
pp. 169-172 ◽  
Author(s):  
E. Xifré-Pérez ◽  
L. F. Marsal ◽  
J. Ferré-Borrull ◽  
J. Pallarès
Keyword(s):  
Refractive Index ◽  
Porous Silicon ◽  
Refractive Index Contrast ◽  
Index Contrast ◽  
Low Refractive Index

Comparison of numerical methods for light propagating in fibers with high steps of refractive index

2012 ◽  
Vol 20 (1) ◽  
Author(s):  
K. Zegadło ◽  
M. Karpierz
Keyword(s):  
Refractive Index ◽  
Numerical Methods ◽  
Light Propagation ◽  
Chromatic Dispersion ◽  
Three Dimensional ◽  
Complex Structures ◽  
Two Dimensional ◽  
Approximate Methods ◽  
Fast Development ◽  
Numerical Tools

AbstractFast development of complex structures like microstructural fibers, photonic nanowires or slot waveguides requires numerical tools to predict a light propagation. There are many works concerning weakly guided case, but the microstructural fibers need algorithm for a high step of the refractive index. In this paper, three approximate methods are compared. The comparison concerns a structure consisting of circular cores surrounded by cladding for different values of the refractive index steps. Application of these methods in chromatic dispersion case is also presented. It is shown that certain conditions prefer two dimensional scalar algorithms (based on approximated methods) than three dimensional ones. This allows us to implement more efficient and less complicated methods.

Refractive index contrast in porous silicon multilayers

2009 ◽  
Vol 6 (7) ◽  
pp. 1721-1724 ◽  
Author(s):  
R. Nava ◽  
M. B. de la Mora ◽  
J. Tagüeña-Martínez ◽  
J. A. del Río
Keyword(s):  
Refractive Index ◽  
Porous Silicon ◽  
Refractive Index Contrast ◽  
Index Contrast
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