[13a-2C-1~11] 4.1 Plasmonics

▲ [13a-2C-3] Highly tunable hybrid plasmonic devices for trapping nano-objects.

〇(P)Marios Sergides¹, Viet Giang Truong¹, Sile Nic Chormaic¹ (1.Okinawa Institute of Science and Technology)

Keywords:plasmonics,particle trapping

We study the optical properties of a hybrid gold nano-disk and nano-hole array design which demonstrate high plasmon resonances in the near-infrared regime (NIR) and is suitable for nano-object manipulation. The tunability of the device is associated with the variation of different parameters such as the periodicity, and dimensions of the different components of the array. The resonance modes of this hybrid design exhibit splittings to low and high energy modes caused by the electromagnetic interference between the disk and hole plasmons. The devices are excited at a glass-water interface by evanescent fields. The enhancement in the NIR is in the biologically compatible part of the spectrum where low photo damage is desirable. Characterization curves of the devices are obtained by collecting spectrometric measurements from the reflected light at the prism-water interface. Furthermore, the nano-rings are connected by grooves that act as trapping sites. In this region, further enhancement and confinement of the local fields are observed. The dependency of the plasmon resonance frequency on both the incident light angle and polarization are studied. These dependencies are also investigated during trapping experiments. Two means of fabrication of the devices are also discussed: Electron Beam Lithography (EBL) followed by Electron Beam Deposition (EBD), and Focused Ion Beam (FIB) etching.