Characteristics Of Light Transmission And Preparation Of Novel 1D Photonic Crystals

Photonic crystals (PCs), are periodic dielectric, or metallic structures, which possess a variety of band dispersions, and band gaps, where the propagation is prohibited for certain ranges of wavelengths. Using different materials or by adjusting geometrical parameters, the propagation of light can be modified virtually in any way we need in a controllable manner. The formation of photonic structures is from the simplest 1D stack to 2D papilionaceous wings, and to the complicated 3D opals. Even though, the scale invariant nature of the governing Maxwell’s equations enables the study of electromagnetic phenomena in the first place, without being held back by structural complexities. A similar advantage is also present from a observation point of view; that is, the lack of confinement in spatial directions in 2D or 1D PC structures does not hinder the investigation of certain EM phenomena. Having said this, keeping the structural uniformity while scaling the PCs down to optical wavelengths is still a challenging problem, especially in three-dimensions (3D). Numerous fabrication techniques are investigated in the last decade, such as alternating layer deposition and etching process for 3D PCs, and electron lithography in combination with dry etching for 2D PCs. The investigation of PCs was quickly spread over a wide range of photonics applications in the last decade of twenty century, gearing towards micro-and nanoscale to be used in telecommunication and optical wavelengths. In this background we deal with some theoretical and experimental work in the thesis such as:1. Calculate the PBGs of 1D and 2D photonic crystals with finite difference time domain (FDTD) and transfer matrix method (TMM). The relational parameters for fabrication of photonic crystals are educed to guide the next work.2. Fabricate 1D Ag-SiO2 system and SiO2-TiO2 system PCs with super high vacuum electron beam vapor method on quartz substrate. PCs with different period and periodic constants are prepared for the analysis.3. The effects of different film thickness, periods and materials to the PBGs are researched by measuring the spectra of transmittance, reflectance and absorption of different PCs comparing with the theoretic results. Rules of preparation for 1D photonic crystals are summarized.4. The blue-shift action in variable periods PCs are observed from comparing with the normal PCs, and the reason of this action is discussed by theoretic computation.5. The absorption enhancement in metallic-dielectric PCs are found from comparing the dielectric and the metallic-dielectric PCs. The influence of the materials thickness and layers are discussed and the reason of this phenomenon is theoretically analysed.