Long-wave infrared surface plasmon grating coupler.

We present a simplified analytic formula that may be used to design gratings intended to couple long-wave infrared radiation to surface plasmons. It is based on the theory of Hessel and Oliner (1965). The recipe is semiempirical, in that it requires knowledge of a surface-impedance modulation amplitude, which is found here as a function of the grating groove depth and the wavelength for silver lamellar gratings at CO(2) laser wavelengths. The optimum groove depth for photon-to-surface-plasmon energy conversion was found by experiment and calculation to be approximately 10%-15% of the wavelength. This value is about twice what has been reported previously in the visible spectral range for sinusoidal grating profiles.

[1]  Richard Soref,et al.  Longwave plasmonics on doped silicon and silicides. , 2008, Optics express.

[2]  A. A. Oliner,et al.  A New Theory of Wood’s Anomalies on Optical Gratings , 1965 .

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

[4]  D. Maystre,et al.  Quantitative theoretical study of the plasmon anomalies of diffraction gratings , 1977 .

[5]  Richard A. Soref,et al.  IR permittivities for silicides and doped silicon , 2010 .

[6]  R. Magnusson,et al.  Filter-response line shapes of resonant waveguide gratings , 1996 .

[7]  D. Heitmann,et al.  Radiative decay of surface plasmons excited by fast electrons on periodically modulated silver surfaces , 1977 .

[8]  R. McPhedran,et al.  A Detailed Theoretical Study of the Anomalies of a Sinusoidal Diffraction Grating , 1974 .

[9]  Lord Rayleigh,et al.  On the Dynamical Theory of Gratings , 1907 .

[10]  P. Bandaru,et al.  Effect of surface texture and geometry on spoof surface plasmon dispersion , 2008 .

[11]  P. Vincent,et al.  Some studies on the behaviour of surface impedance in the vicinity of gratings , 1977 .

[12]  Luis Martín-Moreno,et al.  Transmission and focusing of light in one-dimensional periodically nanostructured metals , 2002 .

[13]  A. Friesem,et al.  Resonant grating waveguide structures , 1997 .

[14]  Andrew G. Glen,et al.  APPL , 2001 .

[15]  R. Depine,et al.  A Simple Model for a Microrough Diffraction Grating That Predicts Diffuse Light Bands , 1989 .

[16]  A. V. Kats,et al.  Nonzeroth-order anomalous optical transparency in modulated metal films owing to excitation of surface plasmon polaritons: An analytic approach , 2004 .

[17]  Thomas W. Ebbesen,et al.  Surface-plasmon circuitry , 2008 .

[18]  R. Magnusson,et al.  Resonant Brewster filters with absentee layers. , 2002, Optics letters.

[19]  Daniel Maystre,et al.  The total absorption of light by a diffraction grating , 1976 .

[20]  R. Apter,et al.  A Detailed Experimental Study of the Anomalies of a Sinusoidal Diffraction Grating , 1973 .

[21]  R. Wood.  XLII. On a remarkable case of uneven distribution of light in a diffraction grating spectrum , 1902 .

[22]  I. Pockrand,et al.  Resonance anomalies in the light intensity reflected at silver gratings with dielectric coatings , 1976 .

[23]  A. Maradudin,et al.  Resonant response of a bare metallic grating to S-polarized light , 1986 .

[24]  Richard A. Soref,et al.  Silicides for infrared surface plasmon resonance biosensors , 2008 .

[25]  R. Wood,et al.  On a Remarkable Case of Uneven Distribution of Light in a Diffraction Grating Spectrum , 1902 .