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Abdelaziz I.,Tunisian National Institute of Applied Sciences and Technology | Abdelmalek F.,Tunisian National Institute of Applied Sciences and Technology | Ademgil H.,University of Kent | Haxha S.,University of Kent | And 2 more authors.
Journal of Lightwave Technology | Year: 2010

There is interest in photonic crystal fibers (PCFs) that possess a large effective area. We demonstrate that it is possible to design a PCF structure configuration with an effective mode area as high as 3000 μm2. The proposed PCF structures consist of five air-hole rings, where the air hole diameters are different from one ring to another. In the second ring six air holes are alternatively removed. The effective mode area of the proposed structure was calculated and compared with effective mode areas reported in literature. It is shown that the effective mode area is enhanced compared to other structures. Additionally, critical propagation properties such as chromatic dispersion, confinement losses, bend losses and nonlinear coefficient of proposed PCF structures are reported thoroughly. © 2010 IEEE.


Abdelaziz I.,Tunisian National Institute of Applied Sciences and Technology | Ademgil H.,University of Kent | Abdelmalek F.,Tunisian National Institute of Applied Sciences and Technology | Haxha S.,University of Kent | And 2 more authors.
Optics Communications | Year: 2010

A photonic crystal fiber (PCF) is proposed that, through novel design, achieves an enhanced effective mode area. The PCF is composed of two concentric elliptical cores. The central core is un-doped silicon whilst the second, outer core region, is doped. The outer doped region is also bordered by lightly doped half ellipse segments. The effective mode area of the structure was calculated and compared with the mode area of conventional PCF's. Our results show that the mode area and chromatic dispersion are very sensitive to the geometry, dimensions and placement of the lightly doped segments. The chromatic dispersion, bend losses and the nonlinear coefficient are also numerically simulated and presented in this paper. © 2010 Elsevier B.V. All rights reserved.


Derbali J.,Tunisian National Institute of Applied Sciences and Technology | Derbali J.,Quantum Physics and Photonics Group | Abdelmalek F.,Tunisian National Institute of Applied Sciences and Technology
Optics Communications | Year: 2015

Dual refraction effect based on the overlapping bands in a two dimensional (2D) photonic crystal (PhC) is demonstrated. The PhC consists of alumina rods with a dielectric constant ε=8.9, arranged in a square lattice in air. To disperse light which has special excitation frequency and a specific incident angle, by this PhC we optimize his structural parameters such as the radius of dielectric rods). It is shown that two focusing phenomena are formed in the PhC image plan; the degeneracy of modes can be applied to realize optical interference and wave front division. The simulation results are obtained by employing the PWM for analyzing bands structure and the finite-difference time-domain (FDTD) to predict the evolution of the electric fields. © 2015 Elsevier B.V. All rights reserved.


Aroua W.,Quantum Physics and Photonics Group | Aroua W.,Jazan University | Abdelmalek F.,Quantum Physics and Photonics Group | Abdelmalek F.,Jazan University | And 3 more authors.
IEEE Journal of Quantum Electronics | Year: 2014

A new design of an optical isolator based on photonic transitions in the interbands of a honeycomb structure that generates a dual negative refraction in a photonic crystal is presented. The involved photonic transition is associated to the perturbation of the dielectric constant of the medium. The band structure is determined using the plane wave method where the transmission spectra, field profile, and mode amplitudes are obtained by applying the finite difference time domain method. Due to the time-dependent perturbation of the refractive index of the medium that constitutes the dual negative refraction, asymmetric transmission mechanism is achieved for one of the desired modes, demonstrating optical isolation. Using the dual negative refraction effect in photonic crystal structure, the optical isolation is reported for only one of the desired optical modes. It is anticipated that the proposed mode conversion mechanism can be employed for designing ultrahigh-speed optical interconnections. The proposed optical isolator model is expected to have a significant impact on designing ultrahigh-speed integrated optical platforms. © 1965-2012 IEEE.

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