In order to further improve the performance of positive feedback surface plasmas（R-SPP）in the asymmetric waveguide structure

we design a new type of planar asymmetric structure of waveguide in this paper.We study the oscillation characteristics of the propagation distance function under certain value of incident angle and wavelength.The analysis shows that long-distance transmission SPP mode can be achieved by changing the angle of incidence at the certain value of the thickness of the core.It is shown that 5to 50 !m propagation distance can be achieved under the incident wavelength of 700

1

500 nm range.It is noted that the traditional SPP propagation distance is limited to be about 2 !m.However

the design of the structure can increase the maximum transmission distance up to 50 !m.The results have certain theoretical and practical significances in the application of new photonic device based on SPP.