Surface plasmon polariton waveguides with subwavelength confinement*

Project supported by the National Natural Science Foundation of China (Grant Nos. 11704266 and 11774245), the Fok Ying Tung Education Foundation, China (Grant No. 151010), the Scientific Research Base Development Program of Beijing Municipal Commission of Education, China, the General Foundation of Beijing Municipal Commission of Education, China (Grant No. KM201810028006), and the Training Program of the Major Research Plan of Capital Normal University, China.
Yang Longkun1, Li Pan1, Wang Hancong2, Li Zhipeng1, †
       

(color online) (a) Illumination of optical excitation: I denotes the input and D is the other end of the wire. (b) Optical image: the bright spot on the left is the focused exciting light. The arrow indicates the light scattered from the wire end. (c) SNOM image of the SPPs on a nanowire excited by 785 nm. (d) Cross-cut along the chain dotted line in (c), reproduced from Ref. [89]. (e) SEM image of a silver nanowire on a monolayer MoS2. (f) Magnified SHG image at the overlap region when the SPPs on the nanowire are excited at the left end. (g) Calculated SHG intensity at a plane located 1.3 μm from the monolayer MoS2. The scale bar is 2 μm in (e) and 500 nm in (f) and (g). (h) Intensity profiles along the Ag nanowire, corresponding to the dashed lines in (f) and (g), respectively, reproduced from Ref. [90].