By means of the transfer matrix method, transmission spectra and dispersion relationships of photonic crystals (AB) m (CD) n (AB) m (CD) n (AB) m are investigated herein. The number and highness of transmission peaks are found to relate closely with the repeating periodicity n, and (CD)n medium of positive- or negative- refractive index as well. The results may be helpful for designing optical filters of desired properties.
This paper focuses on manipulating thermal emission and radiation loss of heat energy in a heat waveguide. A One-Dimensional Photonic Crystal is used as a waveguide clad to prohibit the thermal emission from escaping. The model may reduce the radiation loss of heat energy in the waveguide core, and heat energy can be confined to propagate along the waveguide’s longitude axis. The waveguide clad comprises alternative layers of high and low refractive index materials containing sufficient electromagnetic stop bands to trap the thermal emission from escaping out of the waveguide. The numerical simulation of the model shows that the forbidden bandgap of photonic crystal structures with alternative layers of silica and silicon has width enough to make heat energy be confined within the waveguide core so that efficient heat energy transmission can be achieved along the longitude axis of the waveguide.