半导体光电, 2016, 37 (4): 505, 网络出版: 2016-09-12
内嵌镜像对称矩形腔楔形金属狭缝阵列的宽带增强透射
Broadband Enhanced Transmission through Wedge-shape Metallic Slits Array Embedded with Mirror Symmetric Rectangular Cavities
表面光学 镜像对称矩形腔 楔形金属狭缝阵列 时域有限差分法 增强透射 optics at surfaces mirror symmetric rectangular cavities wedge-shape metallic slits array finite-difference time-domain method enhanced transmission
摘要
采用时域有限差分法研究了内嵌镜像对称矩形腔长度、宽度及其位置对楔形金属狭缝阵列结构透射特性的影响。研究发现, 采用此结构形成的光子晶体结构所产生的能带可以调控禁带, 不仅在短波长范围存在明显的传输禁带, 而且在长波长范围具有较好的增强透射, 表明这种内嵌镜像对称矩形腔进一步破坏了类法布里-珀罗腔共振条件, 更有利于短波长范围表面等离激元能量局域在腔内, 同时提高长波长范围的透射率。矩形腔位置是影响传输禁带和透射特性的主要因素, 其越接近中心位置, 禁带越宽, 透射率越高; 矩形腔厚度主要影响禁带宽度, 厚度为140nm时, 禁带宽度可达236nm; 矩形腔长度主要影响透射特性, 长度为260nm时, 透射率可达95%。
Abstract
The effects of length, width and position of embedded mirror symmetric rectangular cavities on transmission property of wedge-shape metallic slits array were studied using the finite-difference time-domain method. The results show that the generated energy band can control forbidden band by formative photonic crystal structure, the structure makes obvious forbidden band of transmission existing in short-wavelength range, and meanwhile it has enhanced transmission in long-wavelength range. It shows that the proposition of embedded with mirror symmetric rectangular cavities further destroys the resonance condition of Fabry-Perot-like cavity. It’s beneficial for energy of surface plasmon polariton to localize in cavity in short-wavelength range, meanwhile it improves the transmittance in long-wavelength range. The position of rectangular cavity is the main factor affecting the forbidden band of transmission and transmission property: when it approaches the central location, the forbidden band is wider and the transmittance is higher. The thickness of rectangular cavity mainly influences the width of forbidden band: when the thickness is 140nm, the width of forbidden band can be 236nm. The length of rectangular cavity influences the transmission property: when the length is 260nm, the transmittance can be 95%.
肖功利, 郑龙, 王宏庆, 杨宏艳, 邓进丽, 李琦. 内嵌镜像对称矩形腔楔形金属狭缝阵列的宽带增强透射[J]. 半导体光电, 2016, 37(4): 505. XIAO Gongli, ZHENG Long, WANG Hongqing, YANG Hongyan, DENG Jinli, LI Qi. Broadband Enhanced Transmission through Wedge-shape Metallic Slits Array Embedded with Mirror Symmetric Rectangular Cavities[J]. Semiconductor Optoelectronics, 2016, 37(4): 505.