الفهرس 
ContentsOnly 14 pages are availabe for public view
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Abstract
A new design of circular porous core photonic crystal fiber (CCPCF) is introduced and studied for Terahertz propagation with an ultra-low-loss. The effective index, effective mode area, dispersion, material and bending losses of the suggested design are studied using full vectorial finite-element method (FVFEM). The CCPCF with high cladding air filling factor and porous core exhibits ultra-low material absorption loss of 0.022 cm-1 at a frequency of 1.0 THz. Further, very low bending losses of 2.2×10-18 cm-1 can be achieved for 1.0 cm bending radius at 1.0 THz with low confinement loss of 1.37×10-5 cm-1. Additionally, an ultra-flat low dispersion of 0.61 ± 0.035 ps/THz/cm can be reached inside the frequency band from 0.8 to1.0 THz. Therefore, the reported CCPCF has a strong potential for transmission in the Terahertz regime. Another novel porous core PCF (PC-PCF) is suggested and studied for terahertz waveguiding. The PC-PCF has a TOPAS background material with suspended asymmetric slotted core. Therefore, high birefringence of 0.09 is achieved with small material absorption losses of 0.016 cm-1 and 0.028 cm-1 for the quasi transverse electric (TE) and quasi transverse magnetic (TM) modes, respectively at f = 1.5 THz. Additionally, low bending losses of 2.63 ×10-24 cm-1 and 8.16×10-36 cm-1 are obtained for the quasi TE and quasi TM modes, respectively at 1.0 cm bending radius and f =1.5 THz. Further, the PC-PCF has an ultra-flat low dispersion of 0.54±0.08 ps/THz/cm and 0.94±0.1 ps/THz/cm for the quasi TE and TM modes, respectively within the frequency range of 0.8-1.2 THz. Therefore, this reported SSCPCF also has a strong potential for usage in the Terahertz regime. This thesis is organized as follows: Chapter-1: Introduction. Chapter-2: Describes the PCF, its applications, and its guiding mechanisms. Chapter-3: Focuses on the mathematical methods which can be used to study the proposed model. Chapter-4: Presents the design criteria and simulation of the ultra-low loss and flat dispersion circular porous core PCF for terahertz waveguiding in addition to the analysis of the losses, power fraction, and effective area, etc. The analysis mainly depends on the adjustment of the geometrical parameters to achieve a minimum possible loss for the proposed PCF/device. Further, this chapter will study the fabrication availability and simplicity of the suggested PCF. Chapter-5: Presents the design criteria and simulation of ultra-high birefringent suspended slotted core PCF for terahertz waveguiding and will follow the analysis introduced in chapter 5. Chapter-6: Presents the conclusion and the future work in terahertz applications.