Photons produced in the SPDC process typically propagate through optical elements such as waveguides, lenses
and beam splitters. We aim to exploit unconventional optical elements, whose fabrication has recently become
possible due to the rapid development of nanotechnologies. Such miniaturized devices are typically integrated
on microchips that may later become parts of larger quantum circuits. An example is provided by metamaterials,
which are periodic arrays of metallic nanoparticles. These nanoparticles support surface plasmon polaritons -
hybrid excitations that combine electromagnetic fields with coherent oscillations of valence-electron plasma. Here
we experimentally characterize in free space a nanostructural beam splitter, which was designed to feature 25 % of reflection and transmission, and 50 % of absorption. Furthermore we experimentally show quantum interference in that device.
|