The effect of groove on the light transmission through nano-apertures

A few series of metal-coated nano-apertures with and without periodic groove structures have been fabricated on several kinds of pyramid-type probes with different metal thickness. And the influence of the periodic grooves as well as the metal thickness on the light transmission has been examined. The transmitted light intensity from the sub-wavelength size aperture with surrounding grooves was observed to be stronger than that from the aperture without grooves as the apertures on metal plates. And the transmitted light intensity was observed to decrease exponentially as metal thickness increases. The details of fabrication and the light transmission measurement will be discussed with the accompanying simulation results based on finite-difference time-domain method.