Enhanced surface plasmon polariton propagation length using a buried metal grating

We report an enhancement in the propagation length of surface plasmon polaritons (SPPs) on a metallic grating when the grating is buried in the substrate. A template-stripping technique has been used to fabricate the buried grating. Near-field measurements on the buried and an exposed grating show that the full width at half maximum of the surface plasmon resonances are reduced to 57% for the prism-coupled SPPs and 77% for the grating-coupled SPPs. The reduction in the full width at half maximum is attributed to a decrease in the in-plane directional scattering of the SPPs on the buried grating. The propagation lengths of the SPPs measured beyond the gratings are close to the theoretical SPP propagation length on an ideal gold surface. The buried grating with a significant reduction in the full width at half maximum of the surface plasmon resonances is theoretically shown to improve the figure of merit of grating-incorporated SPR sensors.

[1]  D. Heitmann,et al.  Grating couplers for surface plasmons excited on thin metal films in the Kretschmann-Raether configuration , 1999 .

[2]  Suntak Park,et al.  Resonant coupling of surface plasmons to radiation modes by use of dielectric gratings. , 2003, Optics letters.

[3]  Günter Gauglitz,et al.  Surface plasmon resonance sensors: review , 1999 .

[4]  T. Odom,et al.  Screening plasmonic materials using pyramidal gratings , 2008, Proceedings of the National Academy of Sciences.

[5]  Spatial distribution and near-field coupling of surface plasmon polariton Bloch modes , 2008 .

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

[7]  Roger Petit,et al.  Electromagnetic theory of gratings , 1980 .

[8]  M. C. Hutley,et al.  Polarisation Conversion through the Excitation of Surface Plasmons on a Metallic Grating , 1990 .

[9]  H. Offerhaus,et al.  Near-field observation of spatial phase shifts associated with Goos-Hänschen and Surface Plasmon Resonance effects. , 2008, Optics express.

[10]  Stephan Herminghaus,et al.  Thermally induced emission of light from a metallic diffraction grating, mediated by surface plasmons , 1999 .

[11]  R. McPhedran,et al.  Enhanced SPR sensitivity using periodic metallic structures. , 2007, Optics express.

[12]  Sang‐Hyun Oh,et al.  Ultrasmooth Patterned Metals for Plasmonics and Metamaterials , 2009, Science.

[13]  Manfred Hammer,et al.  Amplitude and phase evolution of optical fields inside periodic photonic structures , 2003 .

[14]  W. Barnes,et al.  Coupling effciency of surface plasmon polaritons to radiation using a corrugated surface; angular dependence , 2002 .

[15]  William L. Barnes,et al.  REVIEW ARTICLE: Surface plasmon polariton length scales: a route to sub-wavelength optics , 2006 .

[16]  R. H. Ritchie.  Plasma Losses by Fast Electrons in Thin Films , 1957 .

[17]  Claude S. Lindquist,et al.  Surface analysis algorithms for scanning probe microscopy , 1995 .

[18]  N. Vogel,et al.  Characterization of gold films by surface plasmon spectroscopy: Large errors and small consequences , 2009 .

[19]  R. W. Christy,et al.  Optical Constants of the Noble Metals , 1972 .

[20]  Kuipers,et al.  Local observations of phase singularities in optical fields in waveguide structures , 2000, Physical review letters.