摘要
表面等离子体波导能够突破光的衍射极限,提供亚波长的模式局域性。由于其独特的性质,表面等离子体波导引起了广泛的关注。但是,之前报道的各种表面等离子体波导基本没有涉及到波导结构的可调谐性.这里,我们提出了一种类楔形表面等离子体波导,用有限元方法(FEM)研究了该表面等离子体波导的模式特性。该类楔形表面等离子体波导可以实现超深的亚波长的模式局域性,通过改变波导的结构参数,我们可以对波导的模式局域性和传输损耗进行调控。
Surface plasmon polariton(SPP) waveguides have been paid extensive attention for their unique properties, such as breaking the diffraction limit of light and providing subwavelength mode confinement.Surface plasmonic waveguides proposed before scarcely involve the tunability of the mode confinement and propagation loss by adjusting the geometric parameters. Here, a wedge-like surface plasmonic waveguide is proposed and its properties are investigated by finite element method(FEM). The wedge-like surface plasmonic waveguide features ultra-deep subwavelength mode confinement. The mode confinement and attenuation of the wedge-like surface plasmonic waveguide axe controllable by adjusting the waveguide parameters, which makes the wedge-like surface plasmonic waveguide more flexible and could meet different requirements for mode area and propagation length at the same wavelength.
引文
[1] Barnes W L, Dereux A, Ebbesen T W. Surface plasmon subwavelength optics[J]. Nature, 2003, 424(6950):824830.
[2] Zayats A V, Smolyaninov I I, Maradudin A A. Nano-optics of surface plasmon polaritons[J]. Physics Reports,2005, 408(3-4):131314.
[3] Pitarke J M, Silkin V M, Chulkov E V, et al. Theory of surface plasmons and surface-plasmon polaritons[J].Reports on Progress in Physics, 2007, 70(1):187.
[4] Gramotnev, D K, Bozhelvonyi S I. Plasmonics beyond the diffraction limit[J]. Nature Photonics, 2010, 4(2):8391.
[5] Berini P. Plasmon-polariton waves guided by thin lossy metal films of finite width:bound modes of symmetric structures[J]. Physical Review B, 2000, 61(15):10484503.
[6] Berini P. Plasmon-polariton waves guided by thin lossy metal films of finite width:bound modes of asymmetric structures[J]. Physical Review B, 2001, 63(12):125417.
[7] Vernon K C, Gramotnev D K, et al. Channel plasmon-polariton modes in V grooves filled with dielectric[J].Journal of Applied Physics, 2008, 103(3):034304.
[8] Bozhevolnyi S I, Volkov V S, et al. Channel plasmon-polariton guiding by subwavelength metal grooves[J].Physical Review Letters, 2005, 95(4):046802.
[9] Moreno E, Garcia-Vidal F J, et al. Channel plasmon-polaritons:modal shape, dispersion, and losses[J]. Optics Letters, 2006, 31(23):3447-3449.
[10] Bozhevolnyi S I. Effective-index modeling of channel plasmon polaritons[J]. Optics Express, 2006, 14(20):9467-9476.
[11] Zenin V A,Volkov V S, Han Z H, et al. Dispersion of strongly confined channel plasmon polariton modes[J].Journal of the Optical Society of America B, 2011, 28(7):1596-1602.
[12] Dai D X, He S L. A silicon-based hybrid plasmonic waveguide with a metal cap for a nano-scale light confinement[J]. Optics Express, 2009, 17(19):16646-16653.
[13] Salvador R, Martinez A, Garcia-Meca C, et al. Analysis of hybrid dielectric plasmonic waveguides[J]. IEEE Journal of Selected Topics in Quantum Electronics, 2008, 14(6):1496-1501.
[14] 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.
[15] Zhang Z L, Wang J. Long-range hybrid wedge plasmonic waveguide[J]. Scientific Reports, 2014, 4:6870.
[16] Wang Meiting, Zhou Chunliang, Gou Jia, et al. Hybrid surface plasmonic photonic crystal waveguide[J]. Chinese Journal of Quantum Electronics(量子电子学报),2017,34(4):507-512(in Chinese).
[17] Chen Jinbin, Lu Yonghua, Tao Jun, et al. Investigation on propagation loss of silver nanowire plasmonic waveguides[J].Chinese Journal of Quantum Electronics(量子电子学报),2012,29(2):252-256(in Chinese).
[18] Wu Bowen, Huang Zhixiang, Wang Lihua, et al. Propagation characteristics of surface plasmonic waveguide with metalic elliptical[J].Chinese Journal of Quantum Electonics(量子电子学报),2018, 35(2):252-256(in Chinese).
[19] 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.
[20] Moreno E, Rodrigo S G, Bozhevolnyi S I, et al. Guiding and focusing of electromagnetic fields with wedge plasmon polaritons[J]. Physical Review Letters, 2008, 100(2):023901.
[21] Aspnes D E, Studna A A. Dielectric functions and optical-parameters of Si, Ge, GaP, GaAs, GaSb, InP, InAs,and InSb from 1.5 to 6.0 ev[J]. Physical Review B, 1983, 27(2):985.
[22] Johnson P B, Christy R W. Optical constants of the noble metals[J]. Physical Review B, 1972, 6(12):4370.
[23] Reddy J N. An Introduction to the Finite Element Method[M]. McGraw-Hill New York, 1993.
[24] Oulton R F, Bartal G, Pile D F P, et al. Confinement and propagation characteristics of subwavelength plasmonic modes[J]. New Journal of Physics, 2008, 10(10):105018.
[25] Zia R, Selker M D, Catrysse P B, et al. Geometries and materials for subwavelength surface plasmon modes[J].Journal of the Optical Society of America A, 2004, 21(12):2442-2446.
[26] Berini P. Long-range surface plasmon-polaritons[J]. Advances in Optics and Photonics, 2009, 1(3):484-588.