Near dispersion-less surface plasmon polariton resonances at a   metal-dielectric interface
  Omni-directional light coupling to surface plasmon polariton (SPP) modes to make use of plasmon mediated near-field enhancement is challenging. We report possibility of near dispersion-less modes in structures with unpatterned metal-dielectric interfaces having 2-D dielectric patterns on top. We show that the position and dispersion of the excited modes can be controlled by the excitation geometry and the 2-D pattern. The anti-crossings resulting from the in-plane coupling of different SPP modes are also shown. 
Sachin Kasture, P. Mandal, Amandev Singh, Andrew Ramsay, Arvind S.   Vengurlekar, S. Dutta Gupta, V. I. Belotelov, and Achan...
cond-mat.mtrl-sci cond-mat.other physics.optics