Refractive index, photonic bandgap materials

Middle-IR transmitting films, rare-earth doped snlfide films and snlfide films for other applications also need further study. According to the properties of specific sulfide compounds, one can chose the most suitable method to prepare sulfide films and bulk materials. Since sulfide glasses have high refractive index, sol-gel derived sulfides can also be used to infiltrate silica or polystyrene opals, in order to obtain inverse opal structures for photonic bandgap devices. 

The photonic crystal (PhC) [92. 93], the optical analogue of electronic crystals, consists of two or more kinds of materials. Blocks of materials of different refractive indexes appear alternately, producing a periodic structure. The emergence of photonic bandgap (PBG) is the most important phenomenon that is associated with PhCs. Light with wavelength matching the structural periodicity is rejected in a certain direction incident upon the periodic structure. In the case where the rejection occurs at all directions, the PhC... 

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