| Photonic crystals (PCs) is one of the basic research topics in the optoelectronics fields. PCs can be used to fabricate Photonic Crystal Fiber/High Performance Reflective Mirror/ Photonic Crystal Waveguide/ Photonic Crystal Microcavity and so on,which will have important applications in the future. But up to now the scientists are not very clear about the PCs physical mechanism. And it is very difficult to fabricate PCs,especially these applied in optical communications region .Therefore we focus our attention on the following three facets: 1.Theoretical calculation and design of the 2D A12O3 based PCs whose the band gap located at the THz spectra . Ameliorate the 2D InP based photonic crystal laser that laser can be emitted in single mode and single wavelength; 2. Ultra-high vacuum electron beam evaporation was employed to fabricate ID ultraviolet/visible light PCs(visible light PC means the band gap located at the visible region); 3. Had done some researches on the enhanced absorption effect in the ID metallo-dielectric PCs at the visible/infrared wavelength region .Calculations and designs of 2D PCs band gap:The Plane Wave method was used to calculate the 2D Al2O3 based PC band gap in THz spectra. 2D PCs ,three different structures where the circular air holes in triangular/square /honeycomb lattice fabricated by drilling in Al2O3 substrate ,were calculated. The filling factor r/a was set at 0.3,0.35,0.4,0.43,0.45,0.47,0.5 respectively.According to the calculation results,we can conclude that at the same r/a value the triangular lattice is the easiest way to form photonic band gap than the square lattice and honeycomb lattice. And the width of photonic band gap in triangular lattice is the widest.We also design the 2D Al2O3 PCs which the midgap lies in 150um(f=2THz) with the air holes arranged in triangular lattice .The latticeconstant a and the air holes radius r are 73.Sum and 33.1um respectivrly.Calculated the InP based 2D photonic band gap.We bringforward a method to fabricate 2D photonic crystal lasers, which could be emitted in single-mode and single-wavelength by importing a line defect .ID ultraviolet/visible light region PCs fabrication :The ultra-high vacuum electron beam evaporation was used to fabricate the ID ultraviolet /visible light PC. Ag and SiO? films were deposited on the quartz substrate alternately.The influence of the different period numbers on the photonic band gap was studied.We also found that thickness of SiO2 film has influence on the photonic band gap.When the thickness of SiC>2 film decreased from 120nm to lOOnm, the photonic band gap shifted from 500nm-550nm (green light region) to 330nm-350nm (ultraviolet light region) and this experiment provides the foundations for fabrication of the PCs devices and 2D,3D PCs .The simulation results of 12-layer Ag/SiO2 and 12-layer SIO2/TIO2 system are in good agreement with experimental results.We design the ID SiO2/TiC>2 photonic crystal vertical microcavity fabricated by ultra-high vacuum electron beam evaporation ,whose band gap located at visible/infrared light region .The enhanced absorption effect of ID metallo dielectric PC at the ultraviolet /visible light range: It is the first time that we experimentally demonstrate the enhance absorption effect not only in visible light region but also in infrared region by inserting the periodic dielectric into bulk metal to form ID metallo-dielectric PCs.With the increase of period numbers ,the absorption of ID metallo-dielectric PCs increases. The average absorption of 2-layer,6-layer,12-layer Ag/ SiOi system ID metallo-dielectric PCs in visible light region are 40% , 61% , 84% respectively.We theoretically analyze the unique phenomena observed in reflectivity/transmittance/absorption spectra of Ag/SiO2 SiO2/TiO2, metal Ag film systems. |
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