[1] [1] Maier S A. Plasmonic: Fundamentals and applications［M］. New York: Springer, 2007: 21-25.

[2] [2] Barnes W L, Dereux A, Ebbesen T W. Surface plasmon subwavelength optics［J］. Nature, 2003, 424: 824-830.

[3] [3] Gao L F, Tang L X, Hu F F, et al. Active metal strip hybrid plasmonic waveguide with low critical material gain［J］. Optics Express, 2012, 20(10): 11487-11495.

[4] [4] Chen Yongyi, Tong Cunzhu, Qin Li, et al. Progress in surface plasmon polariton nano-laser technologies and applications［J］. Chinese Optics, 2012, 5(5): 453-463.

[5] [5] Yao Bo, Liu Ye, Long Hu, et al. Spontaneous emission properties of emitters in dielectric-loaded surface plasmon polariton waveguide［J］. Acta Optica Sinica, 2015, 35(8): 0824001.

[6] [6] Wang Jicheng, Jiang Yalan, Wang Yueke, et al. Directional couplers base on MIM plasmonic waveguide structures［J］. Chinese J Lasers, 2015, 42(2): 0217001.

[7] [7] Pile D F, Gramotnev D K. Channel plasmon-polariton in a triangular groove on a metal surface［J］. Optics Letters, 2004, 29(10): 1069-1071.

[8] [8] Ono A, Kato J I, Kawata S. Subwavelength optical imaging through a metallic nanorod array［J］. Physical Review Letters, 2005, 95(26): 267407.

[9] [9] Yatsui T, Abe T, Kourogi M, et al. Plasmon waveguide for optical far/near-field conversion［C］. Conference on Lasers and Electro-Optics, 2003: 4583-4585.

[10] [10] Pile D F P, Ogawa T, Gramotnev D K, et al. Theoretical and experimental investigation of strongly localized plasmons on triangular metal wedges for subwavelength waveguiding［J］. Applied Physics Letters, 2005, 87(6): 061106.

[11] [11] Holmgaard T, Gosciniak J, Bozhevolnyi S I. Long-range dielectric-loaded surface plasmon-polariton waveguides［J］. Optics Express, 2010, 18(22): 23009-23015.

[12] [12] Li Zhiquan, Peng Tao, Zhang Ming, et al. Nanolaser based on hybrid plasmonic waveguide［J］. Chinese J Lasers, 2016, 43(10): 1001005.

[13] [13] Avrutsky I, Soref R, Buchwald W. Sub-wavelength plasmonic modes in a conductor-gap-dielectric system with a nanoscale gap［J］. Optics Express, 2010, 18(1): 348-363.

[14] [14] Li Z Q, Piao R Q, Zhao J J, et al. A low-threshold nanolaser based on hybrid plasmonic waveguides at the deep subwavelength scale［J］. Chinese Physics B, 2015, 24(7): 441-447.

[15] [15] Bian Y, Zheng Z, Zhao X, et al. Nanowire based hybrid plasmonic structures for low-threshold lasing at the subwavelength scale［J］. Optics Communications, 2013, 287(2): 245-249.

[16] [16] Oulton R F, Sorger V J, Genov D A, et al. A hybrid plasmonic waveguide for subwavelength confinement and long-range propagation［J］. Nature Photonics, 2008, 2(8): 496-500.

[17] [17] Liu J T, Xu B Z, Zhang J, et al. Gain assisted indented plasmonic waveguide for low-threshold nanolaser applications［J］. Chinese Physics B, 2012, 21(10): 107303.

[18] [18] Olyaeefar B, Khoshsima H. Low-loss ultra-subwavelength hybrid plasmonic waveguide based on metallic bump structures［J］. Journal of Physics D: Applied Physics, 2014, 47(10): 289-290.

[19] [19] Lu Q, Zou C L, Chen D, et al. Extreme light confinement and low loss in triangle hybrid plasmonic waveguide［J］. Optics Communications, 2014, 319(9): 141-146.

[20] [20] Maziar P N, Kevin T, Yeshaiahu F. Gain assisted propagation of surface plasmon polaritons on planar metallic waveguide［J］. Optics Express, 2004, 12(17): 4072-4079.

[21] [21] Sun R, Dong P, Feng N N, et al. Horizontal single and multiple slot waveguides: Optical transmission at lambda=1550 nm［J］. Optics Express, 2007, 15(26): 17967-17972.

[22] [22] Dai D X, Shi Y C, He S L, et al. Gain enhancement in a hybrid plasmonic nano-waveguide with a low-index or high-index gain medium［J］. Optics Express, 2011, 19(14): 12925-12936.

[23] [23] Mu J, Chen L, Li X, et al. Hybrid nano ridge plasmonic polaritons waveguides［J］. Applied Physics Letters, 2013, 103(13): 131107.

[24] [24] Zou C L, Sun F W, Xiao Y F, et al. Plasmon modes of silver nanowire on a silica substrate［J］. Applied Physics Letters, 2010, 97(18): 183102.

[25] [25] Jacob T R, Kyle P, Oskar P, et al. First-principle derivation of gain in high-index-contrast waveguides［J］. Optics Express, 2008, 21(16): 16659-16669.