Liu Wenjie, Wang Guoxuan, Wen Kunhua, Hu Xiaolong, Qin Yuwen
Opt Lett. 2022 Feb 1;47(3):621-624. doi: 10.1364/OL.447489.
We propose a unidirectional surface plasmon polariton (SPP) launcher with high coupling efficiency and long propagation length. The structure consists of a metallic slanted grating and a metal film that are separated by a SiO layer on a quartz substrate. By inserting the SiO layer, strong interaction between the metal grating and metal film can significantly increase the conversion of incident light into SPPs. Meanwhile, due to the characteristics of the smooth interface between metal film and substrate, the dissipation of SPP originating from the propagation process will be remarkably reduced. Numerical simulations show that this structure with 11 grating periods will obtain high contrast and efficiency of launching. Compared with the rough metal-quartz interface, the smooth one can improve the efficiency of light conversion to SPPs by more than 22.6% and extend the propagating distance by approximately 158%.
我们提出了一种具有高耦合效率和长传播长度的单向表面等离激元极化激元（SPP）发射器。该结构由一个金属倾斜光栅和一个金属膜组成，它们被石英衬底上的SiO层隔开。通过插入SiO层，金属光栅和金属膜之间的强相互作用可以显著提高入射光向SPP的转换。同时，由于金属膜与衬底之间界面光滑的特性，源于传播过程的SPP耗散将显著降低。数值模拟表明，这种具有11个光栅周期的结构将获得高对比度和发射效率。与粗糙的金属-石英界面相比，光滑界面可将光转换为SPP的效率提高超过22.6%，并将传播距离延长约158%。
