遠紅外線表面電漿子元件之研究

Abstract

本論文中探討表面電漿子及類表面電漿子在元件中扮演的角色及物理意義。利用其特性製作出遠紅外線表面電漿子元件包含濾波器以及熱輻射器。 首先是二維週期性金屬孔洞薄膜於GaAs 基板的遠紅外線類表面電漿子濾波器。當光激發(GaAs/metal) (1,0) SSP簡併模態時產生很強的異常穿透效應，其穿透率和穿透頻譜半高寬達到最佳，成功做出4THz以下窄頻砷化鎵遠紅外線濾波器。並藉由實驗結果排除表面電漿子效應，釐清異常穿透現象物理機制。 第二部分提出利用高參雜基板上的長週期二維光柵，同時激發包含(真空/ N型砷化鎵) (1,0)、(1,1)、(2,0)、(2,1)、(2,2) SPP簡併模態的寬頻遠紅外線熱輻射器，有別於一般短週期一維光柵做出的窄頻遠紅外線熱輻射器。 第三部分是(金屬/氮化矽/N型砷化鎵)三層結構遠紅外線表面電漿熱輻射器，在不改變半導體參雜濃度條件之下，利用改變金屬光柵週期或氮化矽層厚度改變多層結構表面電漿子耦合特性，提出一個可改變輻射頻段的窄頻遠紅外線熱輻射器。

In this thesis, the role and the physical origin of surface plasmon and spoof surface plasmon in our devices are investigated. Using these special phenomena, we fabricate far-infrared surface plasmon devices. First, far-infrared spoof surface plasmon filter is fabricated by depositing a 2D metal holes array on GaAs substrate. When light exciting (GaAs/metal) (1,0) SSP modes, a strong EOT phenomenon is observed. By using the phenomenon above, we can fulfill a narrow-band far-infrared filter working under 4 THz. Furthermore, we exclude the role of surface plasmon in EOT phenomenon by the experiment results. Second, a broadband far-infrared thermal emitter is proposeed by exciting (vacuum/N-GaAs) (1,0), (1,1), (2,0), and (2,1) SPP modes simultaneously with the help of the long period 2D grating on the N-GaAs substrate. The bandwidth of devices is proportional to the grating period directly. Third, the (metal/silicon nitride/N-GaAs) trilayer far-infrared surface plasmon thermal emitter, without changing the doping concentration of N-GaAs substrate, we can change the (metal/silicon nitride/N-GaAs) SPP modes by simply changing the period of the upper metal grating or the thickness of silicon nitride layer. The radiation frequency changeable far infrared narrow-band thermal emitter is fabricated.