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https://ptsldigital.ukm.my/jspui/handle/123456789/464237| Title: | Complex structured optical mediums with special emphasis on liquid crystal guides and metamaterial thin films |
| Authors: | Shayan Moghaddas (P78314) |
| Supervisor: | Pankaj Kumar Choudhury, Prof. Dr. |
| Keywords: | Liquid crystals Thin films Metamaterials Electromagnetism Universiti Kebangsaan Malaysia -- Dissertations Dissertations, Academic -- Malaysia |
| Issue Date: | 30-Apr-2019 |
| Description: | The present work is an investigation based on electromagnetic activities inside of complex optical mediums. This thesis is divided into two main sections. The first section concentrates on power confinement regarding hybrid mode, transverse electric mode and transverse magnetic mode through the three layer optical fiber in micro scale dimension. The cross section of the fiber is oval, while the core and inner clad sections contain homogeneous and isotropic dielectric mediums and outermost clad comprised of anisotropic liquid crystal. For the initial results, TE and TM modes of power confinement regarding three different dimensions of major and minor axis due to more accurate contrast have been taken into account, whereas for the second part results (hybrid mode), sheath helix structure has been loaded in core-inner clad interface and comparison of power transmission through this guide with and without sheath helix structure is investigated based on various ψ angles. All the related formulas and obtained equations are corresponding the wave propagation system which vitally must be implemented by appropriate boundary conditions exploiting Maxwell鈥檚 electromagnetic fields. Overall, the purpose of this section is to illustrate the privileges of liquid crystal exploit and trend of sheath helix structure influences on the present complex structured optical guide. The second part of this thesis is focused on plasmonic metamaterials and simulation of gold funnel complex structured for microwave filtering on engineered metasurface in CST Microwave Studio software. The present filter is comprised of three layers, namely gold meta-funnels, nano-sized chromium pillars, and silicon dioxide as the substrate. The incoming infrared (IR) waves, coupled with the excited plasmons at the first and second layers, form an excitation, known as deformed plasmon polariton. Asymmetric distribution of localized SPPs takes place owing to the inherent converging plasmonic feature of the gold funnel structure. The development of reflection peaks with different scales at different incidence angles (0o, 40o and 80o ) of the polarized wave in the spectral characteristics makes the structure useful for filtering the IR waves. Moreover, the gold meta-funnel structured filter takes the additional feature of distinguishing the type of polarized incidence wave. It has been found that the transmission remains maximum corresponding to the normal incidence of the TEpolarized waves (0o ), whereas the TM-polarized waves over the same wavelength range are almost blocked for any value of incidence angle. Thus, the existence of transmission peaks corresponding to the TE waves reveals another application of this device as metastructured polarizer filter.,Certification of Master's / Doctoral Thesis" is not available |
| Pages: | 81 |
| Call Number: | TA418.9.L54M634 2019 3 tesis |
| Publisher: | UKM, Bangi |
| Appears in Collections: | Institute of Microengineering and Nanoelectronics / Institut Kejuruteraan Mikro dan Nanoelektronik (IMEN) |
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| File | Description | Size | Format | |
|---|---|---|---|---|
| ukmvital_122472+SOURCE1+SOURCE1.0.PDF Restricted Access | 2.53 MB | Adobe PDF |  View/Open |
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