Surface plasmon polariton waveguides with subwavelength confinement<xref rid="cpb_27_9_094216fn1" ref-type="fn">*</xref><fn id="cpb_27_9_094216fn1"><label>*</label><p>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.</p></fn>

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 Zhipeng^{1, †}

(color online) (a) Model of the structured surface with square holes cut into the PEC. (b) Dispersion relation for spoof surface plasmons on the structured surface, with the asymptotes of the light line at low frequencies and the plasmon frequency at large values of k_||, reproduced from Ref. [66].