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Study On Photonic Crystal Filter For Terahertz

Posted on:2013-08-10Degree:MasterType:Thesis
Country:ChinaCandidate:X J YuanFull Text:PDF
GTID:2248330371462045Subject:Electromagnetic field and microwave technology
Abstract/Summary:PDF Full Text Request
Terahertz (THz) is a term proposed in 1974 by Fleming and refers to the electromagneticwaves which frequency bands within in the region from 0.1 THz to 10 THz. The electromagneticwave is between microwave and infrared wave, known as sub-millimeter and far-infrared waves.Because of the many excellent features such as high transmission, low energy, broadband andfingerprints, since the 1980s, with a series of achievements in the generation technology of theTerahertz wave there has been formed a Terahertz science and technology research boom across theworld. The research and exploitation of Terahertz’s nature is inseparable from a variety of controlTerahertz wave optics and the continuous development of the Terahertz studies make a lot ofdemand for these devices. The concept of‘photonic crystal’was made by E. Yablonovitch and S.John independently in 1987. It is a kind of artificial crystal which is composed of two or more kindsof media in periodic arrangement. The periodicity of the dielectric constant in the photonic crystalstructure will form the photonic band gap (Photonic Band Gap, referred to as PBG). Theelectromagnetic wave which’s frequency fall in the photonic band gap is strictly prohibited topropagate, thus limiting some scope of light to transmit in the photonic crystal, so that let thepeople’s control of photons is possible. The introduction of defects in photonic crystals can form anarrow pass band width within the photonic band gap, so as to achieve the filter function. Given thestakes of high passing rate for some specific frequency Terahertz wave and for other frequencyTerahertz wave of high reflectivity, it can realize the superior performance of Terahertz filter, inorder to improve the system performance. Concerned the lattice size, Terahertz-band photoniccrystal in the experiment and the production process is relatively easy to obtain and it has smallphysical size, light weight and easy to integrate. All of these provide the feasibility to produce thefunctional device with high performance and achieve the actual application in the Terahertz system.Terahertz technology and photonic crystal technology are new focal study fields. This paperaims to analysis the photonic band-gap structure according to the plane wave expansion method andusing the finite difference time domain numerical analysis method to simulate and construct thephotonic crystal filter in Terahertz band. Through the simulation tool to visually simulate thedesigned structure and optimize the structure parameters in order to achieve comparatively goodfiltering quality. Research work can provide useful help and reference for the development ofTerahertz photonic crystal functional devices. At the same time provide certain theoretical basis forthe application of Terahertz technology.
Keywords/Search Tags:THz, photonic crystal, the finite difference time domain method, the plane wave expansion method, band structure, band gap, point defect
PDF Full Text Request
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