Open AccessHighly efficient on-chip excitation of orthogonal-polarized gap plasmons for a dense polarization multiplexing circuit
Author(s) -
Masahiro Ota,
Mitsuo Fukuda
Publication year - 2018
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.26.021778
Subject(s) - materials science , optics , surface plasmon , plasmon , photonic integrated circuit , polarization (electrochemistry) , waveguide , surface plasmon polariton , optoelectronics , excitation , dielectric , photonics , physics , chemistry , quantum mechanics
We propose an on-chip excitation structure for orthogonal-polarized gap plasmons in polarization multiplexing photonic integrated circuits. The structure consists of a Au nanostripe and tapered gap for refractive index matching to a nano-scale gap plasmonic waveguide; it was fabricated on the top surface of a dielectric-stripe-type waveguide. The excitation ratio from the dielectric-stripe-surface mode to the metallic-gap mode was estimated to be 0.79 using the finite-difference time-domain method for a 100-nm-wide, 100-nm-thick gap waveguide. We experimentally observed the gap mode plasmonic intensity distribution using scanning near-field optical microscopy and confirmed the conversion.