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Title: Low-loss waveguiding and detecting structure for surface plasmon polaritons

A simple and low-loss metal/semiconductor surface plasmon polariton (SPP) device consisting of a SPP waveguide and a detector is studied theoretically and experimentally. We demonstrate a simple diffraction structure (a metal grating) where the SPP couples from the waveguide to the detector. The SPP can propagate without large losses at the air/Au interface, and this interface was used for SPP waveguiding. To convert the SPP into an electric signal using internal photoemission, the propagating SPP is coupled into the Au/Si interface by the diffraction structure. The propagation direction of the coupled SPP at the Au/Si interface depends on the slit pitch of the diffraction structure, and the direction can be controlled by adjusting the pitch. The slit pitch is also modeled using a diffraction grating equation, and the results show good agreement with those of simulations using the finite-difference time-domain method. When diffraction structures consisting of a multi-slit structure and a disk array are placed at the end of the waveguide, SPP coupling into the Au/Si interface is also observed. The photocurrents detected at the Au/Si interface are much larger when compared with that detected for the device without the diffraction structure (26 times for the multi-slit structure and 10more » times for the disk array). From the polarization angle dependence of the detected photocurrent, we also confirmed that the photocurrent was caused by the SPP propagating at the air/Au interface.« less
Authors:
;  [1] ;  [2] ; ; ; ;  [1]
  1. Department of Electrical and Electronic Information Engineering, Toyohashi University of Technology, 1-1 Hibarigaoka, Tempaku-cho, Aichi 441-8580 (Japan)
  2. (Japan)
Publication Date:
OSTI Identifier:
22293065
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 104; Journal Issue: 8; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; DIFFRACTION; DIFFRACTION GRATINGS; EQUATIONS; FINITE DIFFERENCE METHOD; GOLD; INTERFACES; METALS; PHOTOCURRENTS; PHOTOEMISSION; PITCHES; PLASMONS; POLARIZATION; POLARONS; SEMICONDUCTOR MATERIALS; SIGNALS; SILICON; WAVEGUIDES