Theory of surface plasmon generation at nanoslit apertures.

In this Letter, we study the scattering of light by a single subwavelength slit in a metal screen. In contrast with previous theoretical works, we provide a microscopic description of the scattering process by emphasizing the generation of surface plasmons at the slit apertures. The analysis is supported by a rigorous formalism based on a normal-mode-decomposition technique and by a semianalytical model that provides accurate formulas for the plasmonic generation strengths. The generation is shown to be fairly efficient for metals with a low conductivity, such as gold in the visible regime. Verification of the theory is also shown by comparison with recent experimental data [H. F. Schouten, Phys. Rev. Lett. 94, 053901 (2005)].

[1]  Charles Vassallo,et al.  Optical Waveguide Concepts , 1991 .

[2]  R A Linke,et al.  Beaming Light from a Subwavelength Aperture , 2002, Science.

[3]  Stephen Gray,et al.  Surface plasmon generation and light transmission by isolated nanoholes and arrays of nanoholes in thin metal films. , 2005, Optics express.

[4]  W. Barnes,et al.  Surface plasmon subwavelength optics , 2003, Nature.

[5]  U. Welp,et al.  Surface plasmons at single nanoholes in Au films , 2004 .

[6]  P. Lalanne,et al.  One-mode model and Airy-like formulae for one-dimensional metallic gratings , 2000 .

[7]  H. Lezec,et al.  Multiple paths to enhance optical transmission through a single subwavelength slit. , 2003, Physical review letters.

[8]  H. Lezec,et al.  Extraordinary optical transmission through sub-wavelength hole arrays , 1998, Nature.

[9]  J P Hugonin,et al.  Use of grating theories in integrated optics. , 2001, Journal of the Optical Society of America. A, Optics, image science, and vision.

[10]  D. Lynch,et al.  Handbook of Optical Constants of Solids , 1985 .

[11]  Christopher Robert Lawrence,et al.  Enhanced microwave transmission through a single subwavelength aperture surrounded by concentric grooves , 2005 .

[12]  H. Raether.  Surface Plasmons on Smooth and Rough Surfaces and on Gratings , 1988 .

[13]  Henri Lezec,et al.  Diffracted evanescent wave model for enhanced and suppressed optical transmission through subwavelength hole arrays. , 2004, Optics express.

[14]  Y. Takakura,et al.  Optical resonance in a narrow slit in a thick metallic screen. , 2001, Physical review letters.

[15]  A. Requicha,et al.  Plasmonics—A Route to Nanoscale Optical Devices , 2001 .

[16]  R. Wannemacher.  Plasmon-supported transmission of light through nanometric holes in metallic thin films , 2001 .

[17]  H. Bethe.  Theory of Diffraction by Small Holes , 1944 .

[18]  E. Eliel,et al.  Plasmon-assisted two-slit transmission: Young's experiment revisited. , 2005, Physical review letters.