【作者】 赵年顺；

【导师】 兰胜；

【作者基本信息】 汕头大学 ， 材料物理与化学， 2007， 硕士

【摘要】 本论文拟通过理论分析和数值模拟方法来分析光子晶体(PC)缺陷的性质和应用。首先，我们通过数值模拟方法观察线性光子晶体缺陷的透射谱，并且分析了缺陷模的位置随缺陷尺寸大小的变化规律，我们发现通过改变缺陷尺寸的大小，缺陷模的位置可以在禁带中任意被调节，最后通过耦合模拟论分析了缺陷模的系列特性。其次，我们基于有限时域差分法的泵浦探测技术对非线性光子晶体缺陷的动力学特性展开数值模拟计算。我们发现，在外界光源的激励下(在此为连续波CW)，光子晶体的缺陷模将会在其线性状态的初始位置和移动的最终位置中间来回和谐的振荡，缺陷模移动的最终位置取决于入射光源的强度。因此，数值模拟所观察到的非线性缺陷模透射谱实际上是透射率在一个振荡周期内的透射动态平均值，紧接着我们建立了一个物理模型分析了缺陷模的动态移动过程，利用物理方法对缺陷模的平均透射率进行求解，发现所求得的结果与数值模拟观察的结果比较吻合，最后我们研究了引入非线性的光子晶体缺陷的非对称单向透射行为，然后基于所研究的性质构建全光二极管，所设计的全光二极管虽然存在了单向透射行为，但是其透射率不大、对比度不高，如何提高光二极管的对比度成为我们研究的重点。最后，通过有限时域差分的数值模拟方法，我们研究了由光子晶体非线性缺陷对耦合的PC分子的单向透射行为，研究重点集中于如何提高所制备的光二极管最大透射率和对比度。研究发现，通过有意的微调所组合的PC缺陷原子的缺陷尺寸，使两缺陷原子谐振腔频率失配，则该非线性PC分子的透射率和对比度都有明显的提高，该由非线性PC分子组成的全光二极管的性能参数品质因子数与由非对称单缺陷PC组成的全光二极管的品质因子数比较提高了有五倍之多。此外，通过对不同入射波频率的比较，发现只有选择适合的入射波频率，全光二极管的才能被最优化。更多还原

【Abstract】 We have investigated the character and applications of photonic crystals (PCs) defects by theoretical analysis and numerical simulation.First, we examine the defect mode of linear PC atoms by numerical simulations. We find that by changing the size of a defect, the resonant frequency of the defect can be tuned within the band gap, then we analysis defect mode by use of the coupled mode theory.Second, we investigate the dynamics of nonlinear photonic crystal (PC) atoms by use of numerical simulations in a pump-probe scheme based on a finite-difference time-domain technique. We find that under the excitation of a continuous wave (CW), the defect mode will be shifted and driven to oscillate harmonically between its initial position and a final position that is dependent on the pump intensity. Therefore, the transmission observed at a certain frequency is actually the time average of the transient values within an oscillation period. Then we established the physical model for the dynamics of nonlinear PC atoms, the transmission spectra for nonlinear PC atoms that resulted from the dynamic shift are calculated and they are in good agreement with the simulation results. Final we investigate the unidirectional transmission behaviors of an asymmetrically confined photonic crystal (PC) defect with Kerr nonlinearity, base on this we construct all-optical diodes.Finally, we investigate the unidirectional transmission behavior of PC molecules consisting of nonlinear defect pairs by the finite-difference time-domain technique. We focus on how to enhance the transmission contrast and maximum transmission of the resulting optical diodes. It is found that by intentionally and properly misaligning the resonant frequencies of the constitutional PC atoms, the transmission contrast as well as the maximum transmission of the nonlinear PC molecules can be significantly improved. The figure of merit that characterizes the performance of optical diodes can be enhanced by a factor of 5 as compared with the optical diodes constructed by single asymmetrically confined PC atoms. In addition, the optimum performance of the optical diodes can be achieved only when the operating frequency is properly chosen.更多还原