tailieunhanh - Wave Propagation 2011 Part 8

Tham khảo tài liệu 'wave propagation 2011 part 8', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Electromagnetic Propagation Characteristics in One Dimensional Photonic Crystal 197 R_F1_ M1 M11 2 10 T _ n4 Cos 941 .2 _ n4 Cos 94 n1 Cos 91 n1 Cos 91 1 M11 2 11 Where r and t is the reflection and transmission and we can also obtain by the same method the components of the transfer matrix method TMM for P - wave. Finally the dispersion relation for the metallic -dielectric photonic band gap MDPBG which describes the relation between the forbidden band K and the frequency ro can be written as 11 1 n n Cos K A_ Cos k2 d2 Cos k3 d3 - I - 2 I Sin k2 d2 Sin k3 d3 2 n n- 12 ffl with k1 _ n k2 _ n- A _ d2 d- Where is A the lattice constant and K is the forbidden band. 3. Results and discussions The periodicity of the permittivity plays the same role for the photons that propagate inside the structure than the atomic potential for the electrons. Leading further this analogy the thicknesses and the index contrast of the photonic crystal determinate many of its optical properties as it does for conduction properties of semiconductors. Playing on these two parameters we can obtain frequency ranges for which light propagation is forbidden in the material and others ranges for which light can propagate. These frequency ranges are also scale dependent. Reducing the size of the elementary cell of the periodic lattice shifts the whole frequency range to higher values. The consequence of this property is the possibility p-pol s-pol mean-pol Fig. 2. The transmittance of p-pol s-pol and the mean pol to Ag-SiO2 structure. 198 Wave Propagation in Materials for Modern Applications p-pol s-pol mean-pol Fig. 3. The transmittance of p-pol s-pol and the mean pol to Au-SiO2 structure. p-pol s-pol mean-pol Fig. 4. The transmittance of p-pol s-pol and the mean pol to Cu-SiO2 structure. to transpose a photonic crystal design from the microwave domain to infrared or visible range. In our results we have studied one dimensional metallic different metals dielectric SiO2 photonic crystals MDPC s