Multifunctional Plasmonic Film for Recording Near-Field Optical Intensity

• Published in: Nano letters 2014-08, Vol.14 (8), p.4687-4693
• Main Authors: Roxworthy, Brian J, Bhuiya, Abdul M, Inavalli, V. V. G. Krishna, Chen, Hao, Toussaint, Kimani C
• Format: Article
• Language: English
• Subjects: Applied sciences; Collective excitations (including excitons, polarons, plasmons and other charge-density excitations); Condensed matter: electronic structure, electrical, magnetic, and optical properties; Cross-disciplinary physics: materials science; rheology; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Electronics; Exact sciences and technology; Materials science; Molecular electronics, nanoelectronics; Nanocrystalline materials; Nanoscale materials and structures: fabrication and characterization; Nanotubes; Physics; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Surface and interface electron states
• ISSN: 1530-6984; 1530-6992
• DOI: 10.1021/nl501788a

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.