2019/10/04 by Sunny Tiwari, Tiwari, Sunny, Chetna Taneja +9
Engineering · #FOS: Physical sciences #Near-Field Optical Microscopy #Optics (physics.optics) #Photonic and Optical Devices #Plasmonic and Surface Plasmon Research
paper · pdf · doi:10.48550/arxiv.1910.01878
openalex publication_date 2019/10/04 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Hybrid mesoscale-structures that can combine dielectric optical resonances\nwith plasmon-polaritons are of interest in chip-scale nano-optical\ncommunication and sensing. This experimental study shows how a fluorescent\nmicrosphere coupled to a silver nanowire can act as a remotely-excited optical\nantenna. To realize this architecture, self-assembly methodology is used to\ncouple a fluorescent silica microsphere to a single silver nanowire. By\nexciting propagating surface plasmon polaritons at one end of the nanowire,\nremote excitation of the Stokes-shifted whispering gallery modes (WGMs) of the\nmicrosphere is achieved. The WGM-mediated fluorescence emission from the system\nis studied using Fourier plane optical microscopy, and the polar and azimuthal\nemission angles of the antenna are quantified. Interestingly, the thickness of\nthe silver nanowires is shown to have direct ramifications on the angular\nemission pattern, thus providing a design parameter to tune antenna\ncharacteristics. Furthermore, by employing three-dimensional numerical\nsimulations, electric near-fields of the gap-junction between the microsphere\nand the nanowire is mapped, and the modes of nanowire that couple to the\nmicrosphere is identified. This work provides a self-assembled optical antenna\nthat combines dielectric optical resonances with propagating-plasmons and can\nbe harnessed in hybrid nonlinear-nanophotonics and single-molecule remote\nsensing.\n