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.

Multi-stage Mirror-Based Planar Structure for Wavelength Division Demultiplexing

2018 ◽  
Vol 39 (3) ◽  
pp. 273-283
Author(s):  
Haythem Bany Salameh ◽  
Khaled Jawarneh ◽  
Ahmed Musa
Keyword(s):  
Refractive Index ◽  
Wavelength Division Multiplexing ◽  
Incident Angle ◽  
Low Cost ◽  
Refractive Index Profile ◽  
Design Parameters ◽  
Inhomogeneous Layer ◽  
Wavelength Division ◽  
Spatial Shift ◽  
Multi Stage

Abstract In this paper, a new design for a demultiplexer device for Wavelength Division Multiplexing (WDM) communication system is proposed. The proposed device consists of an inhomogeneous layer of a semiconductor material with refractive index that is graded according to a given profile. To minimize the size of the proposed device and achieve better spatial shift between the multiplexed wavelengths, several mirrors are placed at different locations inside the device. These mirrors will force the multiplexed light to be reflected before reaching the total internal reflection point. By controlling the different design parameters such as incident angle, the refractive index profile, etc., a small size, low cost and less complexity WDM device can be realized. In the design process, we exploits the ray’s spatial shift that results from the introduced mirrors and the material dispersion. In addition, the effect of the aforementioned design parameters on the amount of spatial shift between the adjacent wavelengths and the size of the device has been investigated. Results show that the proposed design achieves higher spatial shift as well as smaller device size in comparison with precedent WDM device designs.

Highly Efficient Solar Energy Conversion Using Graded-index Metamaterial Nanostructured Waveguide

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Hala J. El-Khozondar ◽  
Rifa J. El-Khozondar ◽  
Abhishek Sharma ◽  
Kawsar Ahmed ◽  
Vigneswaran Dhasarathan
Keyword(s):  
Refractive Index ◽  
Absorption Spectrum ◽  
Solar Cell ◽  
Incident Angle ◽  
Normal Incidence ◽  
Refractive Indices ◽  
Transmission Matrix ◽  
Graded Index ◽  
Transmission Matrix Method ◽  
Tunable Absorption

AbstractIn this paper, a graded-index metamaterial (GIM) nanostructured waveguide is proposed to enhance the performance of solar cells via a tunable absorption spectrum. The proposed four-layer nanostructured waveguide consists of two GIM and SiNx films which are squeezes between glass substrate and air. Using a transmission matrix method, the transmittances as well as the reflectance are calculated for different film thicknesses, refractive indices and incidence angles. We demonstrate that the reflectance is nearly zero where SiNx refractive index is 2.2 in vicinity of 620 nm. As the incident angle increases, the minimum reflectance wavelength blueshifts and slightly increase in the value. In addition, the variation in the minimum reflectance due to a change in the thickness of SiNx layer studied in detail. We show that the absorbance of a solar cell can be easily controlled by varying refractive index and/or thickness of SiNx layer in the proposed nanostructure. The result shows that the best efficiency occurs at normal incidence, n2 = 2.2, and d2 = 30 nm.

A Novel Demultiplexing Design for Coarse WDM: Exploiting Material Dispersion

2017 ◽  
Vol 38 (3) ◽  
Author(s):  
Haythem Bany Salameh ◽  
Mohammad Al-Rabaie ◽  
Abdallah Khreishah ◽  
Raed Al-Zubi
Keyword(s):  
Refractive Index ◽  
Wavelength Division Multiplexing ◽  
Low Cost ◽  
Homogeneous Medium ◽  
Semiconductor Material ◽  
Material Dispersion ◽  
Wavelength Division ◽  
Coarse Wavelength Division Multiplexing

AbstractIn this paper, a compact low-cost simple-to-fabricate demultiplexer is proposed for coarse wavelength division multiplexing (CWDM). The device consists of two layers of the same semiconductor material: the first layer is homogeneous medium with a given refractive index

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.

Excitation-dependent material dispersion in graded-index fibres

1982 ◽  
Vol 18 (2) ◽  
pp. 100 ◽  
Author(s):  
K.-F. Klein ◽  
W.E. Heinlein ◽  
K.-H. Witte
Keyword(s):  
Material Dispersion ◽  
Graded Index ◽  
Graded Index Fibres

scholarly journals Study of Optical Fiber Design Parameters in Fiber Optics Communications

2017 ◽  
Vol 2 (3) ◽  
pp. 302-308 ◽  
Author(s):  
Salim Qadir Mohammed ◽  
Asaad M. Asaad M. Al-Hindawi
Keyword(s):  
Optical Fiber ◽  
Fiber Optics ◽  
Numerical Aperture ◽  
Design Parameters ◽  
Light Sources ◽  
Long Distance ◽  
Graded Index ◽  
Large Bandwidth ◽  
Telecommunication Infrastructure ◽  
Distance Communication

Fiber optics is an important part in the telecommunication infrastructure. Large bandwidth and low attenuation are features for the fiber optics to provide gigabit transmission. Nowadays, fiber optics are used widely in long distance communication and networking to provide the required information traffic for multimedia applications. In this paper, the optical fiber structure and the operation mechanism for multimode and single modes are analyzed. The design parameters such as core radius, numerical aperture, attenuation, dispersion and information capacity for step index and graded index fibers are studied, calculated and compared for different light sources.

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