CAJ | 학술논문

采用本征模展开法(EME)结合完全匹配层(PML)边界条件,研究了由TiO2和SiO2复合膜结构组成的平面光子晶体Bragg微腔的模式特性,分析了介质厚度无序对微腔模式的调制以及入射角对局域长度的影响.结果表明,若光束正入射,带边局域长度要大于禁带局域长度,随着无序度的增加光子通带的透过率逐渐降低,而禁带的透过率逐渐上升.当无序度较小时,局域长度随随机度的变化在带边和禁带内表现出相反的规律.当无序度较大时,局域长度不仅和随机度、带隙有关,还受到材料的影响;若光束斜入射,TE模的局域长度要远小于TM模对应的值,且其最小值向短波方向移动.此外,入射角和膜层数的变化都会导致局域长度的起伏.
채용본정모전개법(EME)결합완전필배층(PML)변계조건,연구료유TiO2화SiO2복합막결구조성적평면광자정체Bragg미강적모식특성,분석료개질후도무서대미강모식적조제이급입사각대국역장도적영향.결과표명,약광속정입사,대변국역장도요대우금대국역장도,수착무서도적증가광자통대적투과솔축점강저,이금대적투과솔축점상승.당무서도교소시,국역장도수수궤도적변화재대변화금대내표현출상반적규률.당무서도교대시,국역장도불부화수궤도、대극유관,환수도재료적영향;약광속사입사,TE모적국역장도요원소우TM모대응적치,차기최소치향단파방향이동.차외,입사각화막층수적변화도회도치국역장도적기복.
Based on eigen-mode expansion method (EME) and perfectly matched layer (PML) absorbing boundary condition, the properties of the mode of planar photonic crystal Bragg cavity, which was composed of TiO2and SiO2 bi-layers,were investigated. The study of localization behavior in a randomly layered medium was extended from normal to oblique incidence,and both TE and TM modes were considered. The effects of disorder and incident angle on the mode and the localization length of the cavity are studied in detail. The localization length was found to be very small in gaps and much larger in edge regions.The transmission decreases in edges while increases in gaps as the disordering degree increases .The results show that when light incidents upon the system and if the disordering degree is small, the localization length of the edge is lager than the one in the gap, and their relationship with disordering degree is different. When the disordering degree increases, localization length is affected not only by disordering degree and photonic band gap, but also the material. Moreover, the localization length can be changed with period and incident angle, and its behaviors are very different for TE and TM modes.