低維度奈米點表面電漿極化子雷射之研究

Abstract

表面電漿極化子是電荷波與光的耦合極化子。表面電漿極化子擁有能將超高密度的光場侷限於小於繞射極限範圍的特性，可以被應用在半導體微影製程、超高密度元件整合、生物與生醫觀測等領域，吸引了非常多的團隊投入研究。其中在高密度元件整合的光電集成電路應用裡，為了達到更有效率的元件整合而致力於將光學元件縮小，也因此促使了表面電漿子雷射的發展。此外，由於侷域性的光場強度大幅度的提升，也使科學家們能在過去無法探討的弱的光與物質交互作用的領域裡有了更好的延伸方向。為了進一步縮小表面電漿極化子雷射的模態，我們嘗試從改變雷射共振腔的自由度著手。因此在本論文中，利用奈米線與刻有溝槽陣列的銀交錯結合的方式，讓表面電漿極化子於兩者的交界處形成一維的雷射共振腔，能達到更高的侷限性。同時在文章裡我們也將過去文獻裡的傳統奈米線置於平面基板上的二維表面電漿極化子雷射相比，我們所呈現的一維表面電漿極化子雷射擁有更小的模態體積與更大的柏賽爾因子(Purcell factor)。

Surface plasmon polariton (SPP) is the combination of oscillated charges wave and light. Some properties of SPP likes Ultra-small mode volume and strongly localized light intensity are benefited to the applications for lithography process, ultra-compact opto-electronic integrated circuits (OEICs), biological detection. In OEICs, scientists are striving to minimize the size of optical devices for efficient integrating, then the plasmonic nanolaser realm are inspired. Furthermore, the enhancement of localized light intensity enable scientists to study on weak interaction between light and matters. In this thesis, we aimed to shrink down the SPP nanolasers’ mode volume by changing the density of states (DOS) of the laser cavity. We used the ZnO nanowire crossover with silver trenches to form the one-dimensional (1-D) laser cavity, that can provide a better confinement of SPP mode. Then we compared the measured results of 1-D SPP nanolaser and 2-D SPP. We can conclude that the mode volume of 1-D SPP nanolaser is around 1.5x10-5 λ^3, which is 100 times smaller than that of the 2-D SPP nanolasers, and the purcell factor of 1-D SPP nanolaser is enhanced due to the extreme localized electric field and ultra small mode volume.