使用等效電路模型設計奈米表面電漿子元件

Abstract

本論文發展了一套用來分析奈米表面電漿子系統的等效電路模型，並且利用此模型來提出三個適用於晶片通訊應用的奈米表面電漿子元件。在等效電路模型中，我們建構了電壓源電路來表示金屬-介電質-金屬(MIM) 奈米表面電漿子系統的輸入波，並基於傳輸線理論，使用了對稱T型電路來描述有限長度MIM 波導，將所建構的等效電路經電路分析後，可獲得此奈米表面電漿子電漿系統的設計參數和光譜響應。接著，我們利用此電路模型來建構三個具有單一直接相連矩形環共振結構的奈米表面電漿子元件，第一個奈米表面電漿子元件為寬頻帶止濾波器，其平坦的阻帶可藉操作雙埠共振腔內的環共振波長和馬氏干涉波長來實現，並且呈現了一個帶止邊緣波長為1300奈米和1800奈米和元件尺寸為200奈米#westeur024#522奈米的元件設計；另兩個奈米表面電漿子元件為三埠不等功率分光器，其中一個不等功率分光器為調整直接相連矩形環共振結構的輸出波導寬度，而另一個則為於共振腔及相同寬度的輸出波導間，插入具有不同寬度比例的四分之一波長波導，當目標分光比為0.5時，基於前者的設計概念，所獲得不等分光器的元件尺寸為275奈米#westeur024#550奈米，而基於後者的設計概念，所獲得不等分光器的元件尺寸為275奈米#westeur024#1150奈米。

We developed an equivalent circuit model to analyze nanoplasmonic systems and used this model to propose three nanoplasmonic devices for the application of on-chip communications. In this equivalent circuit model, we established a source generator circuit to represent the incidence wave in a metal-insulator-metal (MIM) nanoplasmonic system and used symmetric T-shaped equivalent circuits to describe a finite-length MIM waveguide based on the transmission line theory. Then, the design parameters and the spectral responses of this system could be obtained by using electric circuit analysis based on the implemented equivalent circuit. Subsequently, we used this circuit model to construct three nanoplasmonic devices with a single directly-connected rectangular ring resonator. The first was a broadband bandstop filter whose flat stop band is obtained by manipulating the resonant wavelengths of ring resonance and Mach-Zehnder interference in a two-port resonator. A design example with stopband edge wavelengths of 1300 nm and 1800 nm and dimensions of 200 nm #westeur024# 522 nm was demonstrated. The others were three-port unequal power splitters. One was designed by adjusting the output waveguide widths of the directly-connected resonator while the other was obtained by inserting quarter-wavelength waveguides with different width ratio between the resonator and output waveguides with the same widths. The power splitter with splitting ratio of 0.5 based on the former design concept had the dimensions of were shown with of 275 nm #westeur024# 550 nm, and that based on the latter design concept had dimensions of 275 nm #westeur024# 1150 nm.