The plasmon-forbidden deep sub-wavelength transmission with the TE polarization.
As is well-known, the sub-wavelength transmissions and field enhancement are related to the surface plasmon excitation. Here we demonstrate that in two-layer metallic gratings the deep sub-wavelength transmissions is supported with the TE polarization where the surface plasmon mode is forbidden. The new mechanism to the sub-wavelength transmission is discovered to be completely different from the findings in the literatures. we propose a simple resonance condition to classify the resonance types which are responsible for those sub-wavelength transmissions and confirm with numerical simulations. To give a complete explanation of underlying physics, we inspect the near-field phenomenon within the grating slits.
Chen
Minfeng
M
Graduate Institute of Photonics and Optoelectronics National Taiwan University, Taipei, Taiwan 10617, ROC.
Chang
Hung-chun
HC
D003198:Computer Simulation; D017076:Computer-Aided Design; D004867:Equipment Design; D019544:Equipment Failure Analysis; D008027:Light; D008962:Models, Theoretical; D055096:Optical Devices; D012031:Refractometry / Q000295:instrumentation*; D012542:Scattering, Radiation; D020349:Surface Plasmon Resonance / Q000295:instrumentation*