One-dimensional Photonic Crystal Bandgap Properties

Photonic crystal is a new type of artificial microstructured material with characteristic of photonic bandgap (PBG) structure and local mode. And it has peculiar ability of inhibiting spontaneous radiation of atoms and controlling light propagation. It will be widely used in the fields of optical communication, microwave communication, integration optical and many others. One-dimensional (1D) photonic crystal can be made easily due to its simple structure and has the properties of 2D and 3D photonic crystals. This novel optical materials will probably be crucial components in the field of optical communication, so the relevant theoretical researches are valuable and wide application perspectives are expected.The summary of the dissertation is as follows:1 .The historical background, the physical foundation and the main properties (photonic bandgaps and photonic localization) of photonic crystals are introduced in chapter Ⅰ. Different design methods and different theoretical research methods are also compared in this chapter. Finally, possible utilization and main research fields in photonic crystal are listed so that we can set the aim of the present thesis.2.We deduce the basic differential equation of light spreading in photonic crystal and the theory of one dimensional optical transfer matrix from the Maxwell's equation in chapter Ⅱ. This theory has small calculation quantity and high precision in calculation and may calculate photonic band gap properties of photonic crystals.3. The characters of band structure in one-dimensional photonic crystals containing negative refraction materials are discussed in chapter Ⅲ.The main properties of one-dimensional photonic band gap structures that include layers of negative refraction material are analyzed from the explicit dispersion equation. The results show that the photonic crystals containing negative refractionmaterials have wider photonic band gaps which is different from the case of traditional photonic crystals with narrow transmission bands when the two layers have the same optical thickness.The relations between appearing of stop bands and the ratio of refraction index are discussed, the transmission properties in the two type photonic crystals are compared , which might supply a beneficial reference for the usage of the negative material to design and fabricate the high-quality reflector and the multichannel filters.4. Optical response of photonic crystal Heterjunction structure with anonlinear defect is discussed in chapter IV. We consider the general problem of electronmagnetic wave propagation through one-dimensional photonic crystal heterjunction structure with a nonlinear defect, obtain an expression for the optical response of such dielectric superlattices when the nonlinear impurity dielectric constant is in d function approximation. The results show that once the nonlinear medium sandwiched between two photonic crystals and the system exhibits bistability and multistability, discuss the conditions for the onset of bistability and multistability. A comparison between the 8 function approximation and the nonlinear layer of finite width displays qualitatively similar behavior, which might supply a beneficial reference for the design zero threshold laser and nonlinear optical elements.