Plasmon polaritons in metal nanostructures : the optoelectronic route to nanotechnology

In the light of recent advances in subwavelength optics, the development of optical nanodevices is nowadays conceivable. Among the best candidates to act as the elementary components of such devices are nanoscale structures of noble metals. These materials are capable to sustain resonant electron oscillations (plasmons). This phenomenon gives rise to a spectrally selective optical response and a local field enhancement which can be used in the context of nano-optics. Furthermore, it allows to transduce the optical signals into electrical ones (and vice wersa). Here, we demonstrate an optical nanodevice based on plasmon resonances in gold nanostructures. The adequate metal structures were produced by electron-beam-lithography. The basic operating functions of the device, namely signal processing on the nanoscale and its interfacing on the microscale, were experimentally observed in the optical near-field by photon scanning tunneling microscopy. Furthermore, as a numerical method for validation of the near-field observations the Green's Dyadic Technique is pointed out.