Refractive index reconstruction of graded-index buried channel waveguides from their mode intensities

1997 ◽  
Vol 15 (9) ◽  
pp. 1695-1699 ◽  
Author(s):  
M.L. Von Bibra ◽  
A. Roberts
Keyword(s):  
Refractive Index ◽  
Graded Index ◽  
Buried Channel ◽  
Channel Waveguides

scholarly journals Broadband Unidirectional Forward Scattering with High Refractive Index Nanostructures: Application in Solar Cells

Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4421
Author(s):  
Ángela Barreda ◽  
Pablo Albella ◽  
Fernando Moreno ◽  
Francisco González
Keyword(s):  
Refractive Index ◽  
Solar Cells ◽  
Forward Direction ◽  
High Refractive Index ◽  
Incident Radiation ◽  
Antireflection Coating ◽  
Electromagnetic Response ◽  
Silicon Substrates ◽  
Graded Index ◽  
Dielectric Substrates

High refractive index dielectric (HRID) nanoparticles are a clear alternative to metals in nanophotonic applications due to their low losses and directional scattering properties. It has been demonstrated that HRID dimers are more efficient scattering units than single nanoparticles in redirecting the incident radiation towards the forward direction. This effect was recently reported and is known as the “near zero-backward” scattering condition, attained when nanoparticles forming dimers strongly interact with each other. Here, we analyzed the electromagnetic response of HRID isolated nanoparticles and aggregates when deposited on monolayer and graded-index multilayer dielectric substrates. In particular, we studied the fraction of radiation that is scattered towards a substrate with known optical properties when the nanoparticles are located on its surface. We demonstrated that HRID dimers can increase the radiation emitted towards the substrate compared to that of isolated nanoparticles. However, this effect was only present for low values of the substrate refractive index. With the aim of observing the same effect for silicon substrates, we show that it is necessary to use a multilayer antireflection coating. We conclude that dimers of HRID nanoparticles on a graded-index multilayer substrate can increase the radiation scattered into a silicon photovoltaic wafer. The results in this work can be applied to the design of novel solar cells.

A Simple Method for Prediction of Effective Core Area and Index of Refraction of Single-mode Graded Index Fiber in the Low V Region

2014 ◽  
Vol 35 (4) ◽  
Author(s):  
Angshuman Majumdar ◽  
Satabdi Das ◽  
Sankar Gangopadhyay
Keyword(s):  
Refractive Index ◽  
Single Mode ◽  
Index Of Refraction ◽  
Core Area ◽  
Exact Results ◽  
Simple Method ◽  
Graded Index ◽  
Core Areas ◽  
V Region ◽  
User Friendly

AbstractBased on the simple power series formulation of fundamental mode developed by Chebyshev formalism in the low V region, we prescribe analytical expression for effective core area of graded index fiber. Taking step and parabolic index fibers as examples, we estimate the effective core areas as well as effective refractive index for different normalized frequencies (V number) having low values. We also show that our estimations match excellently with the available exact results. The concerned predictions by our method require little computation. Thus, this simple but accurate formalism will be user friendly for the system engineers.

Determining the Graded-Index Profiles of Channel Waveguides by Prism Coupling Method

2010 ◽  
Vol 37 (3) ◽  
pp. 689-695
Author(s):  
杨天新 Yang Tianxin ◽  
邹豪 Zou Hao ◽  
王雷 Wang Lei ◽  
李睿 Li Rui ◽  
王俊龙 Wang Junlong ◽  
...  
Keyword(s):  
Coupling Method ◽  
Graded Index ◽  
Channel Waveguides ◽  
Prism Coupling

Simultaneous measurement of temperature and refractive index with F–P microcavity sensor based on graded-index few mode fiber

2020 ◽  
Vol 455 ◽  
pp. 124577 ◽  
Author(s):  
Xinghu Fu ◽  
Lianxu Liu ◽  
Shuming Huang ◽  
Guangwei Fu ◽  
Wa Jin ◽  
...  
Keyword(s):  
Refractive Index ◽  
Simultaneous Measurement ◽  
Graded Index

Measuring topography and refractive index of channel waveguides with a hybrid AFM-SNOM

1998 ◽  
Vol 16 (3) ◽  
pp. 388-394 ◽  
Author(s):  
A. Mannoni ◽  
F. Quercioli ◽  
B. Tiribilli ◽  
C. Ascoli ◽  
P. Baschieri ◽  
...  
Keyword(s):  
Refractive Index ◽  
Channel Waveguides

Multi-Layer Graded-Index Planar Structure for Coarse WDM Demultiplexing

2019 ◽  
Vol 0 (0) ◽  
Author(s):  
Haythem Bany Salameh ◽  
Hazem Khrais
Keyword(s):  
Refractive Index ◽  
Incident Angle ◽  
Design Parameters ◽  
Material Dispersion ◽  
Wavelength Division ◽  
Graded Index ◽  
Spatial Shift ◽  
Number Of Layers ◽  
Refractive Index Difference ◽  
Device Size

AbstractIn this paper, we develop a novel demultiplexer design for Coarse Wavelength Division Multiplexer (CWDM). The device consists of multi-layer inhomogeneous semi-conductor material, where the refractive index of each layer is graded according to a predefined profile. The proposed design exploits the ray’s spatial shift that results from the material dispersion as different wavelengths propagate through the different layers of the device. Our design forces the multiplexed light to refract after propagation for short distance within the device leading to smaller device size while providing the needed spatial shift between the ray’s of the adjacent multiplexed wavelengths. The proposed structure can be easily implemented using the well-established technology utilized in fabricating existing graded-index fibers. The impacts of the various design parameters (such as the incident angle, number of layers, the layer thickness, the spacing between adjacent wavelengths, the refractive index difference) on the amount of achieved spatial shift between the adjacent wavelengths and the size of the device are investigated. Compared to previous proposed techniques, our device can be easily fabricated to provide higher spatial shift while reducing the device size with by controlling the different design parameters.

scholarly journals Self-Aligned Hierarchical ZnO Nanorod/NiO Nanosheet Arrays for High Photon Extraction Efficiency of GaN-Based Photonic Emitter

Micromachines ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 346
Author(s):  
Won-Seok Lee ◽  
Soon-Hwan Kwon ◽  
Hee-Jung Choi ◽  
Kwang-Gyun Im ◽  
Hannah Lee ◽  
...  
Keyword(s):  
Refractive Index ◽  
Extraction Efficiency ◽  
Hydrothermal Process ◽  
Refractive Index Change ◽  
Zno Nanorod ◽  
Index Change ◽  
Graded Index ◽  
Shell Nanostructures ◽  
Nanosheet Arrays ◽  
Photon Extraction Efficiency

Advancements in nanotechnology have facilitated the increased use of ZnO nanostructures. In particular, hierarchical and core–shell nanostructures, providing a graded refractive index change, have recently been applied to enhance the photon extraction efficiency of photonic emitters. In this study, we demonstrate self-aligned hierarchical ZnO nanorod (ZNR)/NiO nanosheet arrays on a conventional photonic emitter (C-emitter) with a wavelength of 430 nm. These hierarchical nanostructures were synthesized through a two-step hydrothermal process at low temperature, and their optical output power was approximately 17% higher than that of ZNR arrays on a C-emitter and two times higher than that of a C-emitter. These results are due to the graded index change in refractive index from the GaN layer inside the device toward the outside as well as decreases in the total internal reflection and Fresnel reflection of the photonic emitter.

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