The Research On Photonic Band Structures Of Low-Dimension Photonic Crystals

Photonic crystals are artificially fabricated periodic dielectric structures.The periodic dielectric structures have photonic band gap(PBG) and are referred to as photonic band gap materials.The propagation of electromagnetic waves of frequencies within the gaps is forbidden. It is analogues to the case of electrons in semiconductors. Photonic crystals have many noval physical properties which provide a good way to control the propagation of photons. The photonic band gap materials have many potential applications in devices.The applications of photonic crystals are attributed to the special properties of electronic and optic area, and such properties are depend on photonic band structures.Through research on photonic band structures, we can get all important information of any kind of photonic crystals. Unfortunately, we have not maken it clear that the physical process of the formation of PEG by far, and what act important roles in such process is also unknown. Therefore, it is very significent for us to work on photonic band structures.Such work can result in further step on theorical area and provides instruction to fabricate photonic devices.We mainly work on low-dimension photonic crystals(one-dimension and two-dimension). There are some common points in such crystals: simple structures,easier to be fabricated and more wider PBG can be got from such photonic crystals. We can get more meaningful result by studying low-dimension photonic crystals.First ,we work out the photonic band structures of different photonic crystals, then we find out the relationships between photonic band structures and some factors including the dielectric ratio, room ratio and disorders.We draw conclusions that photonic band gaps will get wider when dielectric ratio get bigger, PBG also get wider and rich with the increase of room ratio .We also find that size disorders are more influential than site disorders.Even though the detailed structures of amorphous photonic materials are different with each other, they possess a common photonic gap, if only they have the same short-range order. Based on our studies it may be confirmed that the first band gap of photonic crystals comes mainly from the short-range order, while the higher-order band gaps are related to the long-range order.