一维掺杂光子能隙材料对激光脉冲修饰效应的研究

One dimensional(1D) Photonic crystals(PCs) have many applications in many fields due to the easiness of fabrication and omni-directional Photonic Bandgap(PBG) structures etc. The research is very important to the design of PC devices and some fundamental problems related with strong light localization in periodic structures.The work in this project systematically studied the decoration effects of defects and disorder in 1D Pcs, and some related fundamental problems . All our results can be summarized in the following three sections.A.) Device design and applications: 1) Design a kind of broadband high reflectors by bandgap extension which originates from the combining effect of disorder and Bragg reflection of binary multilayers deviated from λ/4 waveplates;2)The Study of local field enhancement and slow wave effect for 1D with embedded resonant defect. we calculated the distribution of the amplitude of local filed and the density of modes in frequency region, simulating the tunneling time of a light pulse through PCs with finite periods and propose that the strong dispersive properties can be used in the separation of the fast constituent from slow constituent in γ ray by the nuclear exploding. Also we design a kind of 1D X ray PC targets by utilizing the enhancement of the local field at the tunneling frequency; 3)Design of 1D metallo-dielectric quantum well structure, which can be used as electromagnetic shielding windows..B) Some fundamental studies on the effect of disorder and defect to optical propagation in PC and PBG: we studied the density of modes inside or outside the bandgap, and the local field at some characteristic frequencies. There exists two kind of non-propagating modes inside the bandgap, one is evanescent wave with spatial localization, another is extended non-propagating wave, the mechanism is very similar to concepts of the mobility gap and density of states gap of amorphous semiconductors. Also, we developed powerful FDTD/FEM/Plane Wave codes in C++ and Matlab which can solve the spatial and temporal problem of electromagnetic wave and PBG structure by FDTD, FEM and plane wave etc. These codes are very valuable and important to our future work.C)New application in new frequency band, we extend our work about 1D PCs in microwave region recently, design 1D PBG microstrip with quantum well structure etc, and fabricate filter

研究掺杂的一维有限周期光子能隙材料对光的修饰效应的物理机制，样品由介电材料或半导体材料制备，掺杂引入缺陷在带隙中产生局域模，测量局域场的增益效应和空间分布，利用干涉法等测量时间延迟。研究非线性掺杂对激光脉冲的修饰机理，研究弱光下的局阈场效应及其相关应用，开展不同修饰效应的探索性应用研究。