Surface
Plasmon Photonics:
How to get light through a subwavelength
hole"
Metallic films perforated with
sub-wavelength holes (~150 nm) can transmit light with an efficiency thousand
times larger than what theory predicts for single holes. The efficency can even
be larger than the fractional area of the holes, which means that even the
light falling beside the holes emerges on the other side of the sample. This extraordinary transmission is due to
the coupling of the incident light with the surface plasmons of the film. The transmission spectrum contains peaks
attributed to surface-plasmon modes that depend on both the symmetry and the 2D
lattice parameter of the surface corrugation. We have shown that this
phenomenon can also be used to tune and enhance the transmission of single
subwavelength apertures. These results have broad fundamental and practical
implications and show that, with modern fabrication techniques, surface
plasmons can be engineered and controlled to yield unique optical properties.