| This thesis is based on the National National Science Foundation of China "a relevant study of the new mechanism on lasing in random media" and " single photo laser", around the optical transmission properties of photonic crystals,many problems about photonic crystals are studied,such as study of optical properties of a random photonic crystal with NIM-PIM alternant multilayer, the characteristics of mode competition in the micro-cavity of one-demensional ternary photonic crystals, study the micro-cavity structure of the two-dimensional triangular lattice photonic crystal with defects, demonstrate a novel optical switching structure based on a coupled photonic crystal waveguides.The key points of this thesis are presented as follows:1.The introduction of photonic crystals about the research situation and theory method.2. Study the influences from the number of plies of the medium and the thickness to the transmission characteristics of the light by using the design procedure of transmission matrix and the light field distribution in dielectric layer, when the photonic crystals are negative refractive index alternating incident. The results shows that the transmission characteristics of photonic crystals is related to the random degree and the thickness of the dielectric layer. Then we can find that the bandwidth becomes narrow when the transmittivity reduces with the thickness of the dielectric layer is increased, v.v.. Finally, in the dielectric layer, the light appear the local states.3. We present the characteristics of mode competition with gain medium in the micro-cavity of one-demensional ternary photonic crystal with transfer matrix method. From the results, we know that the transmission spectra have the characteristics of mode competition. And then, we also know the central wavelength of the peak transmission and the thickness of the Zno gain medium are matching. In the case of other parameters are appropriate,if we change the thickness of the thickness of the Zno gain medium, the central wavelength of the peak transmission will also be changed. Others if we increase the number of the dielectric layer of photonic crystal or increase the intensity of pumping light, the mode competition will be more pronounced.4. In this paper,we study the micro-cavity structure of the two-dimensional triangular lattice photonic crystal with defects by plane wave expansion method.We can calculate dispersion curves and the distribution of defect mode. Results showed that the wave of the defect mode is consistent with the wavelength of the micro-cavity resonant wave. We simulated the dynamic propagating process in the photonic crystal about electromagnetic wave of the resonant wavelength band by using of the FDTD method, we can figure out the graph of the local mode's space distribution. Finally, we will carry out the tuneable property of the centralwavelength of the resonant wave by using the method of regularly changing the radius of dielectric cylinder around the defect.5. In this paper,we demonstrate a novel optical switching structure based on a coupled photonic crystal waveguides。The switching structure is formed by two closely spaced linear defect waveguides in a two-dimensional photonic crystal of air holes in semiconductor matrix.We investigate fill factor which affects dispersion diagram by using PWM methods. In the coupling region,we found that the input signal beam can be controlled by choosing a appropriate coupling length for exchanging singals between two output ports.The coupling efficiency is increased and the coupling length is also reduced by modifying the fill factor of the coupling region between the coupled waveguides... |
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