| The photonic crystal is the artifical structure whose refractive index is periodically modulated. As the crystal for electromagnetic waves, it has similar properties with the solid crystals existing in the nature. There exists certain photonic band gap in this structure. It means that the electromagnetic waves with the frequency in this band gap will not be able to propagate in this structure. Its appearance made it possible to control the light behavior. The various components based on photonic crystals made the photonic integration promising. In recent years, the theory for photonic crystals develops very fast. More and more new components with special properties are designed. The development of fabrication technique for photonic crystals is not so fast. But the photonic crystals for near-infrared region are available. It is obvious that the research for photonic crystals will bring the great changes to the optical science. Due to the variety of this field, this thesis will only be able to focus on some properties in photonic crystals.As the third generation reflector, the omnidirectional reflector possesses the high reflection within omnidirectional incident angles. Based on this omnidirectional reflector, the new generation fibre, called omni-guide, is developed. The research about omnidirectional reflector will be greatly helpful for this omni-guide fibre. In this thesis, the basic theory for the omnidirectional reflection in one-dimensional photonic crystals is analyzed. The factors affecting the band width of omnidrectional band gap have been analyzed in detail. These works will be very helpful for the design of omnidrectional reflector. Based on these analyses, a new method for the extension of omnidirectional band gap has been developed. This method greatly improves the band width of omndirectional band gap, which makes the omnidirectional reflector for the whole visible region possible. At the same time, this method greatly decreases the demand for the fabrication technique, which makes the omnidirectional reflector with high band width available. Based on this method, the omnidirectional reflector with large band width is fabricated by using conventional coating technology. The result directly proves that this method is very helpful to design the omnidirectional reflector with high band width.The behavior of light in photonic crystals is very different with that in usual materials. It is very complex. The research for the light's behavior in photonic crystals will greatly improve the understanding for the photonic crystals. The negative refraction and superprism in photonic crystals are promising for the near field image and wavelength demultiplexing system. The plane expansion method is widely used in the analysis for the band structures of photonic crystals. But it is very inconvenient for the analysis of light's behavior in it. In this thesis, a new method based on plane expansion method is proposed. Based on this method, the wavevector diagram for photonic crystals can be easily obtained. By using this diagram, the behavior of light in photonic crystals can be analyzed qualitatively. To analyze this behavior in detail, the group veloc ity for the light in photonic crystals is calculated. Based on the wavevector diagram and group velocity, the property of light in photonic crystals can be analyzed quantitatively. In this thesis, the negative refraction, superprism and self-collimated phenomena are analyzed by using this method.The fabrication of high dimensional photonic crystals is very difficult to date, especially for the high dimensional photonic crystals using in the visible region. So in this thesis, we analyze the light's propagation in one dimensional photonic crystals. The method appropriate for the analysis of superprism in one dimensional photonic crystals is analyzed. The factors affecting thesuperprism effect have been analyzed. This greatly helps the design. The researches for superprism property in one-dimensional photonic crystals indicates that it is very difficult t... |
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