In the traditional Kretschmann prism/metal film/air configuration, the p-polarized light can be applied to excite the SPP wave with lower initial admittance compared with and the associated locus of the metal film is plotted in Fig. 1. However, the s-polarized light cannot excite the SPP wave because the s-polarized admittance of air is always negative imaginary when total reflection occurs. The locus of a metal film would never let the locus point go toward the characteristic admittance of a prism to reach a coupling effect. However, the restriction on an s-polarized LRSPP wave can be overcome using a symmetrical cell that is equivalent to a single layer with designed characteristic admittance and phase thickness. The initial admittance can be provided using a periodic multilayer composed of several symmetric cells of the ABA or ABCBA type with designable equivalent characteristic admittance.5 The initial admittances for s- and p-polarization are functions of the angle of incidence θi, the refractive index, and the thickness of each layer in the unit cell. To excite an LRSPP wave on a metal film at a designated angle of incidence θi, both positive imaginary admittances with values larger than the absolute imaginary part of characteristic admittance of metal can be designed by tuning parameters in the unit cell to cause projected s- and p-polarized loci of the metal in the NAD. A coupling multilayer between the prism and the metal film is also designable with the same trick to bring the ends of metal loci to the same terminal, refractive index of prism, to reach a diminished reflectance that is associated with coupling from the light wave to the LRSPP wave.