Multifunctional Plasmonic Film for Recording Near-Field Optical Intensity
Nano Lett.. 2014-07-17; 14(8): 4687-4693
DOI: 10.1021/nl501788a
Read on PubMed
We demonstrate the plasmonic equivalent of photographic film for recording
optical intensity in the near field. The plasmonic structure is based on gold
bowtie nanoantenna arrays fabricated on SiO2 pillars. We show that it can be
employed for direct laser writing of image data or recording the polarization
structure of optical vector beams. Scanning electron micrographs reveal a careful
sculpting of the radius of curvature and height of the triangles composing the
illuminated nanoantennas, as a result of plasmonic heating, that permits spatial
tunability of the resonance response of the nanoantennas without sacrificing
their geometric integrity. In contrast to other memory-dedicated approaches using
Au nanorods embedded in a matrix medium, plasmonic film can be used in multiple
application domains. To demonstrate this functionality, we utilize the structures
as plasmonic optical tweezers and show sequestering of SiO2 microparticles into
optically written channels formed between exposed sections of the film. The
plasmonic film offers interesting possibilities for photonic applications
including optofluidic channels “without walls,” in situ tailorable biochemical
sensing assays, and near-field particle manipulation and sorting.