铝基方环微结构红外吸收特性分析

发布时间：2018-01-16 20:29

本文关键词：铝基方环微结构红外吸收特性分析　出处：《哈尔滨工业大学》2015年硕士论文　论文类型：学位论文

【摘要】：周期性微结构表面在电磁波入射时会表现出一些特殊的辐射特性,比如波长选择性,可通过设计不同微结构表面来对光谱进行主动调控。针对红外探测应用背景,本文设计了一种表面刻成周期性方环阵列排布的二维金属/介质/金属薄膜光栅结构,旨在红外波段3~5μm和8~10μm获得双频高吸收率特性。利用严格耦合波分析(RCWA)方法来计算分析该结构的辐射特性,并对其吸收机理进行研究。二维方环阵列结构对入射电磁波具有极化不敏感特性,通过对方环结构参数进行设计可以在所需波段获得高吸收率峰,其产生的机理可归结为在表层金属与基底之间的介质层中激发了磁极化共振(MP),使入射电磁场能量被强烈束缚在介质层中。随着入射角度的增大会产生表面等离子极化(SPP),MP与SPP相互耦合,使得吸收峰向短波方向移动并且峰值大小逐渐减小。正入射时只激发奇数阶的磁极化共振,而在斜入射的情况下会出现偶数阶的磁极化共振。可以看出MPs不仅具有波长选择性还具有角度选择性的特点。对比分析了方环结构与方贴片结构的吸收特性,可以知道由于方孔空腔的影响会使得高阶磁极化共振的位置向短波方向移动。研究了方环结构吸收带宽的扩宽机制,采用多层堆叠的方式改进了方环结构,在保证吸收峰高度的同时有效的扩宽了吸收峰宽度。随着堆叠层数的增加会使吸收峰的宽度向短波方向扩展。采用嵌套的方式设计了双方环阵列结构和方环加方贴片阵列结构,利用同一结构的不同部分可以在不同的波长位置激发磁极化共振(MPs)来获得双频高吸收率特性。
[Abstract]:Periodic microstructures exhibit some special radiation characteristics, such as wavelength selectivity, when electromagnetic waves are incident. The spectrum can be actively regulated by designing different microstructural surfaces, aiming at the background of infrared detection applications. In this paper, a two-dimensional metal / dielectric / metal thin film grating structure with periodic square ring arrays on the surface is designed. The radiation characteristics of the structure are calculated and analyzed by using the strict coupled wave analysis (RCWA) method, which aims at obtaining the double frequency high absorptivity at 3 渭 m and 8 渭 m in the infrared band. The absorption mechanism is studied. The two-dimensional square ring array structure is not polarization-insensitive to the incident electromagnetic wave, and the high absorptivity peak can be obtained by the design of the structure parameters of the opposite ring. The mechanism of its formation can be attributed to the excitation of magnetic polarity resonance (MPP) in the dielectric layer between the surface metal and the substrate. The incident electromagnetic field energy is strongly trapped in the dielectric layer. With the increase of the incident angle, the surface plasma polarization (SPP) and SPP are coupled with each other. The absorption peak moves towards the shortwave direction and the magnitude of the peak decreases gradually. When the incident is normal, only the odd-order magnetic polarization resonance is excited. In the case of oblique incidence, an even-order magnetic polarity resonance appears. It can be seen that MPs has not only wavelength selectivity but also angular selectivity. The absorption characteristics of square ring structure and square patch structure are compared and analyzed. . It can be known that the position of high order magnetization resonance will move to the direction of shortwave due to the influence of square hole cavity. The absorption bandwidth broadening mechanism of square ring structure is studied and the square ring structure is improved by multilayer stacking. The width of absorption peak is widened effectively while the height of absorption peak is guaranteed. The width of absorption peak will expand to the direction of shortwave with the increase of stacked layers. The array structure of two rings and the square ring addition are designed by nested method. Patch array structure. Using different parts of the same structure to excite the magnetic polarity resonance (MPs) at different wavelength positions, the double frequency high absorptivity can be obtained.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN215;O551.3

【相似文献】