A simple and robust technique to retrieve effective refractive index of heterogeneous dielectrics for millimeter-wave applications

2015 ◽  
Author(s):  
Abdul Aziz ◽  
Ladislau Matekovits ◽  
Aldo De Sabata
Keyword(s):  
Refractive Index ◽  
Millimeter Wave ◽  
Effective Refractive Index

scholarly journals Dielectric Slabs-Based Lens for Millimeter-Wave Beamforming

2022 ◽  
Vol 12 (2) ◽  
pp. 638
Author(s):  
Ali H. Alqahtani ◽  
Yosef T. Aladadi ◽  
Mohammed T. Alresheedi
Keyword(s):  
Refractive Index ◽  
Millimeter Wave ◽  
Effective Refractive Index ◽  
Horn Antenna ◽  
Slab Thickness ◽  
Antenna Element ◽  
Sidelobe Level ◽  
Spherical Lens ◽  
Single Antenna ◽  
Dielectric Lens

This paper proposes a dielectric slabs-based lens for millimeter-wave beamforming systems. The proposed lens is based on the graded steps of the effective refractive index of the semi-spherical lens. It consists of multiple dielectric slabs that match the selected gradient effective refractive index. These slabs have the same thicknesses and different radii. The slab thickness in this lens should not exceed a quarter of the operating wavelength to keep on a similar effective refractive index of the original semi-spherical lens. A horn antenna is used to examine the performance of the designed lens at 28 GHz frequency in terms of the maximum gain, sidelobe level, and 3 dB beamwidth. Sixteen switchable horn antennas are used to demonstrate lens capability for millimeter-wave beamforming. Every single antenna element is selected individually, thus the dielectric lens steers and enhances the corresponding radiation of the selected element in the desired direction.

scholarly journals NONLINEAR OPTICAL WAVEGUIDE STRUCTURE FOR SENSOR APPLICATION: TM CASE

2007 ◽  
Vol 21 (30) ◽  
pp. 5075-5089 ◽  
Author(s):  
HALA M. KHALIL ◽  
MOHAMMED M. SHABAT ◽  
SOFYAN A. TAYA ◽  
MAZEN M. ABADLA
Keyword(s):  
Refractive Index ◽  
Theoretical Analysis ◽  
Closed Form ◽  
Optical Waveguide ◽  
Effective Refractive Index ◽  
Nonlinear Optical ◽  
Waveguide Structure ◽  
Analytical Expressions ◽  
Evanescent Waveguide ◽  
Waveguide Sensor

In this work, we present an extensive theoretical analysis of nonlinear optical waveguide sensor. The waveguide under consideration consists of a thin dielectrica film surrounded by a self-focused nonlinear cladding and a linear substrate. The nonlinearity of the cladding is considered to be of Kerr-type. Both cases, when the effective refractive index is greater and when it is smaller than the index of the guiding layer, are discussed. The sensitivity of the effective refractive index to any change in the cladding index in evanescent optical waveguide sensor is derived for TM modes. Closed form analytical expressions and normalized charts are given to provide the conditions required for the sensor to exhibit its maximum sensitivity. The results are compared with those of the well-known linear evanescent waveguide sensors.

scholarly journals Titania Photonic Crystals with Precise Photonic Band Gap Position via Anodizing with Voltage versus Optical Path Length Modulation

Nanomaterials ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 651 ◽  
Author(s):  
Ermolaev ◽  
Kushnir ◽  
Sapoletova ◽  
Napolskii
Keyword(s):  
Refractive Index ◽  
Photonic Crystals ◽  
Band Gap ◽  
Titanium Oxide ◽  
Effective Refractive Index ◽  
Photonic Band Gap ◽  
Voltage Versus ◽  
Research Attention ◽  
Anodic Titanium Oxide ◽  
Photonic Band

Photonic crystals based on titanium oxide are promising for optoelectronic applications, for example as components of solar cells and photodetectors. These materials attract great research attention because of the high refractive index of TiO2. One of the promising routes to prepare photonic crystals based on titanium oxide is titanium anodizing at periodically changing voltage or current. However, precise control of the photonic band gap position in anodic titania films is a challenge. To solve this problem, systematic data on the effective refractive index of the porous anodic titanium oxide are required. In this research, we determine quantitatively the dependence of the effective refractive index of porous anodic titanium oxide on the anodizing regime and develop a model which allows one to predict and, therefore, control photonic band gap position in the visible spectrum range with an accuracy better than 98.5%. The prospects of anodic titania photonic crystals implementation as refractive index sensors are demonstrated.

scholarly journals Modes Effective Refractive Index Difference Measurement in Few-mode Optical Fiber

2016 ◽  
Vol 140 ◽  
pp. 77-84 ◽  
Author(s):  
Jing Zhang ◽  
Zhifang Wu ◽  
Tianye Huang ◽  
Xuguang Shao ◽  
Ping Shum
Keyword(s):  
Refractive Index ◽  
Optical Fiber ◽  
Effective Refractive Index ◽  
Difference Measurement ◽  
Refractive Index Difference
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