中文摘要：

通过远场聚焦光斑激发银纳米线表面等离子体激元（Surface plasmon polariton，SPP），并搭建银纳米线路由传输结构改变SPP的传输距离，研究了SPP的传输损耗特性。实验上测量了置于玻璃衬底表面的银纳米线在不同激发波长时SPP的传输损耗系数，发现SPP的传输损耗具有波长依赖性：632．8nm激光激发时，传输损耗系数为0．115μpm^-1，780nm激光激发时，传输损耗系数为0．0923pm^-1，即传输损耗系数在长波激发时小，而在短波激发时大。测量结果对基于银纳米线波导的集成微纳光学系统设计有很好的指导作用。

英文摘要：

By the far field excitation and measurement, propagation loss of wire＇s surface plasmon is experimentally investigated with structure of branched-routing silver nanowire. The experimental results show that the propagation loss depends on the exciting wavelength. The coefficient of propagation loss is measured as 0.115 μm^-1 at 632.8 nm and 0.0923 μm^-1 at 780 nm. The propagation loss is smaller at longer wavelength, that is, SPP can propagate further at long-wavelength laser exciting. The measurement contributes to optimizing plasmonic devices based on silver nanowire waveguides.