Abstract

The modal distributions and properties of dielectric and hybrid plasmonic (HP) waveguides are investigated systematically. Their coupling efficiency through a direct coupling scheme is estimated by numerical simulation and the results are compared with values predicted by the Fresnel formula. The influence of various factors on the coupling efficiency between dielectric and HP waveguides, including interface scattering, absorption caused by light coupling to the surface plasmon polariton mode, and the mismatch between the two waveguide modes, is analyzed theoretically. A tapered coupling structure with linearly varying height and width of the silicon layer is proposed, with which extremely high coupling efficiency (94.4%) and good broadband coupling performance (above 90%) are demonstrated.

© 2013 Optical Society of America

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References

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  1. M. Z. Alam, J. Meier, J. S. Aitchison, and M. Mojahedi, “Super mode propagation in low index medium,” in Conference on Lasers and Electro-Optics/Quantum Electronics and Laser Science Conference and Photonic Applications Systems Technologies, OSA Technical Digest Series (CD) (Optical Society of America, 2007), paper JThD112.
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    [CrossRef]
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    [CrossRef]
  4. V. J. Sorger, Z. Ye, R. F. Oulton, Y. Wang, G. Bartal, X. Yin, and X. Zhang, “Experimental demonstration of low-loss optical waveguiding at deep sub-wavelength scales,” Nat. Commun. 2, 331 (2011).
    [CrossRef]
  5. D. K. Gramotnev and S. I. Bozhevolnyi, “Plasmonics beyond the diffraction limit,” Nat. Photonics 4, 83–91 (2010).
    [CrossRef]
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    [CrossRef]
  7. D. Dai and S. He, “A silicon-based hybrid plasmonic waveguide with a metal cap for a nano-scale light confinement,” Opt. Express 17, 16646–16653 (2009).
    [CrossRef]
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    [CrossRef]
  9. D. Dai and S. He, “Low-loss hybrid plasmonic waveguide with double low-index nano-slots,” Opt. Express 18, 17958–17966 (2010).
    [CrossRef]
  10. S. Zhu, G. Q. Lo, and D. L. Kwong, “Theoretical investigation of silicon MOS-type plasmonic slot waveguide based MZI modulators,” Opt. Express 18, 27802–27819 (2010).
    [CrossRef]
  11. M. Wu, Z. Han, and V. Van, “Conductor-gap-silicon plasmonic waveguides and passive components at subwavelength scale,” Opt. Express 18, 11728–11736 (2010).
    [CrossRef]
  12. M. Z. Alam, J. Meier, J. S. Aitchison, and M. Mojahedi, “Propagation characteristics of hybrid modes supported by metal-low-high index waveguides and bends,” Opt. Express 18, 12971–12979 (2010).
    [CrossRef]
  13. I. Avrutsky, R. Soref, and W. Buchwald, “Sub-wavelength plasmonic modes in a conductor-gap-dielectric system with a nanoscale gap,” Opt. Express 18, 348–363 (2010).
    [CrossRef]
  14. S. Zhu, G. Q. Lo, and D. L. Kwong, “Theoretical investigation of silicide Schottky barrier detector integrated in horizontal metal-insulator-silicon-insulator-metal nanoplasmonic slot waveguide,” Opt. Express 19, 15843–15854 (2011).
    [CrossRef]
  15. J. Wang, X. Guan, Y. He, Y. Shi, Z. Wang, S. He, P. Holmström, L. Wosinski, L. Thylen, and D. Dai, “Sub-μm2 power splitters by using silicon hybrid plasmonic waveguides,” Opt. Express 19, 838–847 (2011).
    [CrossRef]
  16. B. Tang, L. Dai, and C. Jiang, “Electromagnetically induced transparency in hybrid plasmonic-dielectric system,” Opt. Express 19, 628–637 (2011).
    [CrossRef]
  17. D. Dai, Y. Shi, S. He, L. Wosinski, and L. Thylen, “Gain enhancement in a hybrid plasmonic nano-waveguide with a low-index or high-index gain medium,” Opt. Express 19, 12925–12936 (2011).
    [CrossRef]
  18. D. Dai, Y. Shi, S. He, L. Wosinski, and L. Thylen, “Silicon hybrid plasmonic submicron-donut resonator with pure dielectric access waveguides,” Opt. Express 19, 23671–23682 (2011).
    [CrossRef]
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    [CrossRef]
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    [CrossRef]
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    [CrossRef]
  23. L. Chen, T. Zhang, X. Li, and W. Huang, “Novel hybrid plasmonic waveguide consisting of two identical dielectric nanowires symmetrically placed on each side of a thin metal film,” Opt. Express 20, 20535–20544 (2012).
    [CrossRef]
  24. Q. Li, Y. Song, G. Zhou, Y. Su, and M. Qiu, “Asymmetric plasmonic-dielectric coupler with short coupling length, high extinction ratio, and low insertion loss,” Opt. Lett. 35, 3153–3155 (2010).
    [CrossRef]
  25. S. Zhu, G. Q. Lo, and D. L. Kwong, “Components for silicon plasmonic nanocircuits based on horizontal Cu-SiO2-Si-SiO2-Cu nanoplasmonic waveguides,” Opt. Express 20, 5867–5881 (2012).
    [CrossRef]
  26. Y. Song, J. Wang, Q. Li, M. Yan, and M. Qiu, “Broadband coupler between silicon waveguide and hybrid plasmonic waveguide,” Opt. Express 18, 13173–13179 (2010).
    [CrossRef]
  27. P. B. Johnson and R. W. Christy, “Optical constants of the noble metals,” Phys. Rev. B 6, 4370–4379 (1972).
    [CrossRef]

2012

2011

2010

2009

2008

R. F. Oulton, V. J. Sorger, D. A. Genov, D. F. P. Pile, and X. Zhang, “A hybrid plasmonic waveguide for subwavelength confinement and long-range propagation,” Nat. Photonics 2, 496–500 (2008).
[CrossRef]

1972

P. B. Johnson and R. W. Christy, “Optical constants of the noble metals,” Phys. Rev. B 6, 4370–4379 (1972).
[CrossRef]

Aitchison, J. S.

M. Z. Alam, J. Meier, J. S. Aitchison, and M. Mojahedi, “Propagation characteristics of hybrid modes supported by metal-low-high index waveguides and bends,” Opt. Express 18, 12971–12979 (2010).
[CrossRef]

M. Z. Alam, J. Meier, J. S. Aitchison, and M. Mojahedi, “Super mode propagation in low index medium,” in Conference on Lasers and Electro-Optics/Quantum Electronics and Laser Science Conference and Photonic Applications Systems Technologies, OSA Technical Digest Series (CD) (Optical Society of America, 2007), paper JThD112.

Alam, M. Z.

M. Z. Alam, J. Meier, J. S. Aitchison, and M. Mojahedi, “Propagation characteristics of hybrid modes supported by metal-low-high index waveguides and bends,” Opt. Express 18, 12971–12979 (2010).
[CrossRef]

M. Z. Alam, J. Meier, J. S. Aitchison, and M. Mojahedi, “Super mode propagation in low index medium,” in Conference on Lasers and Electro-Optics/Quantum Electronics and Laser Science Conference and Photonic Applications Systems Technologies, OSA Technical Digest Series (CD) (Optical Society of America, 2007), paper JThD112.

Avrutsky, I.

Bartal, G.

V. J. Sorger, Z. Ye, R. F. Oulton, Y. Wang, G. Bartal, X. Yin, and X. Zhang, “Experimental demonstration of low-loss optical waveguiding at deep sub-wavelength scales,” Nat. Commun. 2, 331 (2011).
[CrossRef]

R. F. Oulton, V. J. Sorger, T. Zentgraf, R. M. Ma, C. Gladden, L. Dai, G. Bartal, and X. Zhang, “Plasmon lasers at deep subwavelength scale,” Nature 461, 629–632 (2009).
[CrossRef]

Bian, Y.

Bozhevolnyi, S. I.

D. K. Gramotnev and S. I. Bozhevolnyi, “Plasmonics beyond the diffraction limit,” Nat. Photonics 4, 83–91 (2010).
[CrossRef]

Buchwald, W.

Chee, J.

Chen, L.

Chen, S.

Christy, R. W.

P. B. Johnson and R. W. Christy, “Optical constants of the noble metals,” Phys. Rev. B 6, 4370–4379 (1972).
[CrossRef]

Dai, D.

Dai, L.

B. Tang, L. Dai, and C. Jiang, “Electromagnetically induced transparency in hybrid plasmonic-dielectric system,” Opt. Express 19, 628–637 (2011).
[CrossRef]

R. F. Oulton, V. J. Sorger, T. Zentgraf, R. M. Ma, C. Gladden, L. Dai, G. Bartal, and X. Zhang, “Plasmon lasers at deep subwavelength scale,” Nature 461, 629–632 (2009).
[CrossRef]

Gao, D.

Genov, D. A.

R. F. Oulton, V. J. Sorger, D. A. Genov, D. F. P. Pile, and X. Zhang, “A hybrid plasmonic waveguide for subwavelength confinement and long-range propagation,” Nat. Photonics 2, 496–500 (2008).
[CrossRef]

Gladden, C.

R. F. Oulton, V. J. Sorger, T. Zentgraf, R. M. Ma, C. Gladden, L. Dai, G. Bartal, and X. Zhang, “Plasmon lasers at deep subwavelength scale,” Nature 461, 629–632 (2009).
[CrossRef]

Gramotnev, D. K.

D. K. Gramotnev and S. I. Bozhevolnyi, “Plasmonics beyond the diffraction limit,” Nat. Photonics 4, 83–91 (2010).
[CrossRef]

Guan, X.

Han, Z.

Hao, R.

He, S.

He, Y.

Holmström, P.

Huang, K.

Huang, W.

Jiang, C.

Johnson, P. B.

P. B. Johnson and R. W. Christy, “Optical constants of the noble metals,” Phys. Rev. B 6, 4370–4379 (1972).
[CrossRef]

Kwong, D. L.

Li, E.

Li, Q.

Li, W.

Li, X.

Li, Y.-P.

Lo, G. Q.

Lou, F.

Ma, R. M.

R. F. Oulton, V. J. Sorger, T. Zentgraf, R. M. Ma, C. Gladden, L. Dai, G. Bartal, and X. Zhang, “Plasmon lasers at deep subwavelength scale,” Nature 461, 629–632 (2009).
[CrossRef]

Meier, J.

M. Z. Alam, J. Meier, J. S. Aitchison, and M. Mojahedi, “Propagation characteristics of hybrid modes supported by metal-low-high index waveguides and bends,” Opt. Express 18, 12971–12979 (2010).
[CrossRef]

M. Z. Alam, J. Meier, J. S. Aitchison, and M. Mojahedi, “Super mode propagation in low index medium,” in Conference on Lasers and Electro-Optics/Quantum Electronics and Laser Science Conference and Photonic Applications Systems Technologies, OSA Technical Digest Series (CD) (Optical Society of America, 2007), paper JThD112.

Mojahedi, M.

M. Z. Alam, J. Meier, J. S. Aitchison, and M. Mojahedi, “Propagation characteristics of hybrid modes supported by metal-low-high index waveguides and bends,” Opt. Express 18, 12971–12979 (2010).
[CrossRef]

M. Z. Alam, J. Meier, J. S. Aitchison, and M. Mojahedi, “Super mode propagation in low index medium,” in Conference on Lasers and Electro-Optics/Quantum Electronics and Laser Science Conference and Photonic Applications Systems Technologies, OSA Technical Digest Series (CD) (Optical Society of America, 2007), paper JThD112.

Oulton, R. F.

V. J. Sorger, Z. Ye, R. F. Oulton, Y. Wang, G. Bartal, X. Yin, and X. Zhang, “Experimental demonstration of low-loss optical waveguiding at deep sub-wavelength scales,” Nat. Commun. 2, 331 (2011).
[CrossRef]

R. F. Oulton, V. J. Sorger, T. Zentgraf, R. M. Ma, C. Gladden, L. Dai, G. Bartal, and X. Zhang, “Plasmon lasers at deep subwavelength scale,” Nature 461, 629–632 (2009).
[CrossRef]

R. F. Oulton, V. J. Sorger, D. A. Genov, D. F. P. Pile, and X. Zhang, “A hybrid plasmonic waveguide for subwavelength confinement and long-range propagation,” Nat. Photonics 2, 496–500 (2008).
[CrossRef]

Pile, D. F. P.

R. F. Oulton, V. J. Sorger, D. A. Genov, D. F. P. Pile, and X. Zhang, “A hybrid plasmonic waveguide for subwavelength confinement and long-range propagation,” Nat. Photonics 2, 496–500 (2008).
[CrossRef]

Qiu, M.

Shi, P.

Shi, Y.

Song, Y.

Soref, R.

Sorger, V. J.

V. J. Sorger, Z. Ye, R. F. Oulton, Y. Wang, G. Bartal, X. Yin, and X. Zhang, “Experimental demonstration of low-loss optical waveguiding at deep sub-wavelength scales,” Nat. Commun. 2, 331 (2011).
[CrossRef]

R. F. Oulton, V. J. Sorger, T. Zentgraf, R. M. Ma, C. Gladden, L. Dai, G. Bartal, and X. Zhang, “Plasmon lasers at deep subwavelength scale,” Nature 461, 629–632 (2009).
[CrossRef]

R. F. Oulton, V. J. Sorger, D. A. Genov, D. F. P. Pile, and X. Zhang, “A hybrid plasmonic waveguide for subwavelength confinement and long-range propagation,” Nat. Photonics 2, 496–500 (2008).
[CrossRef]

Su, Y.

Tang, B.

Thylen, L.

Van, V.

Wang, G.

Wang, J.

Wang, Y.

V. J. Sorger, Z. Ye, R. F. Oulton, Y. Wang, G. Bartal, X. Yin, and X. Zhang, “Experimental demonstration of low-loss optical waveguiding at deep sub-wavelength scales,” Nat. Commun. 2, 331 (2011).
[CrossRef]

Wang, Z.

Wei, X.

Wosinski, L.

Wu, M.

Xiao, L.

Yan, M.

Ye, Z.

V. J. Sorger, Z. Ye, R. F. Oulton, Y. Wang, G. Bartal, X. Yin, and X. Zhang, “Experimental demonstration of low-loss optical waveguiding at deep sub-wavelength scales,” Nat. Commun. 2, 331 (2011).
[CrossRef]

Yin, X.

V. J. Sorger, Z. Ye, R. F. Oulton, Y. Wang, G. Bartal, X. Yin, and X. Zhang, “Experimental demonstration of low-loss optical waveguiding at deep sub-wavelength scales,” Nat. Commun. 2, 331 (2011).
[CrossRef]

Zentgraf, T.

R. F. Oulton, V. J. Sorger, T. Zentgraf, R. M. Ma, C. Gladden, L. Dai, G. Bartal, and X. Zhang, “Plasmon lasers at deep subwavelength scale,” Nature 461, 629–632 (2009).
[CrossRef]

Zhang, T.

Zhang, X.

V. J. Sorger, Z. Ye, R. F. Oulton, Y. Wang, G. Bartal, X. Yin, and X. Zhang, “Experimental demonstration of low-loss optical waveguiding at deep sub-wavelength scales,” Nat. Commun. 2, 331 (2011).
[CrossRef]

R. F. Oulton, V. J. Sorger, T. Zentgraf, R. M. Ma, C. Gladden, L. Dai, G. Bartal, and X. Zhang, “Plasmon lasers at deep subwavelength scale,” Nature 461, 629–632 (2009).
[CrossRef]

R. F. Oulton, V. J. Sorger, D. A. Genov, D. F. P. Pile, and X. Zhang, “A hybrid plasmonic waveguide for subwavelength confinement and long-range propagation,” Nat. Photonics 2, 496–500 (2008).
[CrossRef]

Zhao, X.

Zheng, Z.

Zhou, G.

Zhou, T.

Zhu, J.

Zhu, S.

J. Lightwave Technol.

Nat. Commun.

V. J. Sorger, Z. Ye, R. F. Oulton, Y. Wang, G. Bartal, X. Yin, and X. Zhang, “Experimental demonstration of low-loss optical waveguiding at deep sub-wavelength scales,” Nat. Commun. 2, 331 (2011).
[CrossRef]

Nat. Photonics

D. K. Gramotnev and S. I. Bozhevolnyi, “Plasmonics beyond the diffraction limit,” Nat. Photonics 4, 83–91 (2010).
[CrossRef]

R. F. Oulton, V. J. Sorger, D. A. Genov, D. F. P. Pile, and X. Zhang, “A hybrid plasmonic waveguide for subwavelength confinement and long-range propagation,” Nat. Photonics 2, 496–500 (2008).
[CrossRef]

Nature

R. F. Oulton, V. J. Sorger, T. Zentgraf, R. M. Ma, C. Gladden, L. Dai, G. Bartal, and X. Zhang, “Plasmon lasers at deep subwavelength scale,” Nature 461, 629–632 (2009).
[CrossRef]

Opt. Express

S. Zhu, G. Q. Lo, and D. L. Kwong, “Theoretical investigation of silicon MOS-type plasmonic slot waveguide based MZI modulators,” Opt. Express 18, 27802–27819 (2010).
[CrossRef]

B. Tang, L. Dai, and C. Jiang, “Electromagnetically induced transparency in hybrid plasmonic-dielectric system,” Opt. Express 19, 628–637 (2011).
[CrossRef]

J. Wang, X. Guan, Y. He, Y. Shi, Z. Wang, S. He, P. Holmström, L. Wosinski, L. Thylen, and D. Dai, “Sub-μm2 power splitters by using silicon hybrid plasmonic waveguides,” Opt. Express 19, 838–847 (2011).
[CrossRef]

D. Dai, Y. Shi, S. He, L. Wosinski, and L. Thylen, “Gain enhancement in a hybrid plasmonic nano-waveguide with a low-index or high-index gain medium,” Opt. Express 19, 12925–12936 (2011).
[CrossRef]

S. Zhu, G. Q. Lo, and D. L. Kwong, “Theoretical investigation of silicide Schottky barrier detector integrated in horizontal metal-insulator-silicon-insulator-metal nanoplasmonic slot waveguide,” Opt. Express 19, 15843–15854 (2011).
[CrossRef]

D. Dai, Y. Shi, S. He, L. Wosinski, and L. Thylen, “Silicon hybrid plasmonic submicron-donut resonator with pure dielectric access waveguides,” Opt. Express 19, 23671–23682 (2011).
[CrossRef]

D. Dai and S. He, “A silicon-based hybrid plasmonic waveguide with a metal cap for a nano-scale light confinement,” Opt. Express 17, 16646–16653 (2009).
[CrossRef]

Y. Bian, Z. Zheng, X. Zhao, J. Zhu, and T. Zhou, “Symmetric hybrid surface plasmon polariton waveguides for 3D photonic integration,” Opt. Express 17, 21320–21325 (2009).
[CrossRef]

I. Avrutsky, R. Soref, and W. Buchwald, “Sub-wavelength plasmonic modes in a conductor-gap-dielectric system with a nanoscale gap,” Opt. Express 18, 348–363 (2010).
[CrossRef]

M. Wu, Z. Han, and V. Van, “Conductor-gap-silicon plasmonic waveguides and passive components at subwavelength scale,” Opt. Express 18, 11728–11736 (2010).
[CrossRef]

M. Z. Alam, J. Meier, J. S. Aitchison, and M. Mojahedi, “Propagation characteristics of hybrid modes supported by metal-low-high index waveguides and bends,” Opt. Express 18, 12971–12979 (2010).
[CrossRef]

Y. Song, J. Wang, Q. Li, M. Yan, and M. Qiu, “Broadband coupler between silicon waveguide and hybrid plasmonic waveguide,” Opt. Express 18, 13173–13179 (2010).
[CrossRef]

D. Dai and S. He, “Low-loss hybrid plasmonic waveguide with double low-index nano-slots,” Opt. Express 18, 17958–17966 (2010).
[CrossRef]

S. Zhu, G. Q. Lo, and D. L. Kwong, “Components for silicon plasmonic nanocircuits based on horizontal Cu-SiO2-Si-SiO2-Cu nanoplasmonic waveguides,” Opt. Express 20, 5867–5881 (2012).
[CrossRef]

L. Chen, T. Zhang, X. Li, and W. Huang, “Novel hybrid plasmonic waveguide consisting of two identical dielectric nanowires symmetrically placed on each side of a thin metal film,” Opt. Express 20, 20535–20544 (2012).
[CrossRef]

J. Chee, S. Zhu, and G. Q. Lo, “CMOS compatible polarization splitter using hybrid plasmonic waveguide,” Opt. Express 20, 25345–25355 (2012).
[CrossRef]

Opt. Lett.

Phys. Rev. B

P. B. Johnson and R. W. Christy, “Optical constants of the noble metals,” Phys. Rev. B 6, 4370–4379 (1972).
[CrossRef]

Other

M. Z. Alam, J. Meier, J. S. Aitchison, and M. Mojahedi, “Super mode propagation in low index medium,” in Conference on Lasers and Electro-Optics/Quantum Electronics and Laser Science Conference and Photonic Applications Systems Technologies, OSA Technical Digest Series (CD) (Optical Society of America, 2007), paper JThD112.

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Figures (7)

Fig. 1.
Fig. 1.

(a) Cross section of HP waveguide. The HP waveguide has three layers. (b) Cross section of dielectric waveguide. The waveguide has two layers. The red, gray, and yellow regions denote silicon nitride, silicon, and gold, respectively.

Fig. 2.
Fig. 2.

(a) Effective index, (b) propagation length, and (c) modal area of HP waveguide as functions of hp at three different values of wp. (d) Effective index of the dielectric waveguide as a function of hg at three different values of wg.

Fig. 3.
Fig. 3.

Modal field distribution of HP waveguide with (a) hp=0.3μm and wp=0.2μm and (b) hp=0.58μm and wp=0.2μm. Modal field distribution of dielectric waveguide with (c) hg=0.3μm and wg=0.2μm and (d) hg=0.58μm and wg=0.2μm.

Fig. 4.
Fig. 4.

(a) Schematic diagram of a direct coupling structure. Influence of height of silicon layer on coupling efficiency η for (b) wp=wg=0.2μm, (c) wp=wg=0.3μm, and (d) wp=wg=0.4μm calculated by the FF (black lines) and simulated by the FDTD (red lines).

Fig. 5.
Fig. 5.

(a) Schematic diagram of tapered coupling structure. The height of Si film is changed linearly from hg to hp in the tapered coupling structure, where hp is fixed at 0.26 μm. (b) Variation of η with hg with tapered coupling length equal to (1) 0 μm, (2) 0.3 μm, and (3) 0.4 μm. The square lines of (b) show the η of structure in (a) as Ltaper equal to 0, 0.3, and 0.4 μm, respectively, while the metallic absorption in the coupling tapered structure is considered. The circular dotted lines of Fig. 6(b) represent the η of structure in (a) as Ltaper equal to 0.3 and 0.4 μm, respectively, when the metal in the coupling region is set to be lossless and the metal loss is ignored.

Fig. 6.
Fig. 6.

(a) Schematic diagram of adjusted tapered coupling structure. The height of Si film is changed linearly from hg to hp, and the width of Si film decreases linearly from wg to wp. (b) Variation of η of this coupler with hg (1) wg=0.3μm, (2) wg=0.4μm. The square dotted lines give the η of the coupler by considering the metallic absorption in the tapered structure. The circular dotted lines give the η of the coupler by setting the metal in the tapered structure to be lossless.

Fig. 7.
Fig. 7.

Variation of η with λ with Ltaper=0.3μm, wg=0.4μm, hg=0.34μm, wp=0.2μm, and hp=0.26μm.

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