Open AccessReversibly tunable plasmonic bandgap by responsive hydrogel grating
Author(s) -
Nityanand Sharma,
Christian Petri,
Ulrich Jonas,
Jakub Dostálek
Publication year - 2016
Publication title -
optics express
Language(s) - Uncategorized
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.24.002457
Subject(s) - materials science , grating , optics , plasmon , surface plasmon , refractive index , optoelectronics , band gap , lithography , interference lithography , surface plasmon resonance , electron beam lithography , fiber bragg grating , wavelength , nanotechnology , resist , nanoparticle , fabrication , layer (electronics) , medicine , alternative medicine , pathology , physics
Reversible actuating of surface plasmon propagation by responsive hydrogel grating is reported. Thermo-responsive poly(N-isopropylacrylamide)-based (pNIPAAm) hydrogel nanostructure was designed and tethered to a gold surface in order to switch on and off Bragg scattering of surface plasmons which is associated with an occurrence of a bandgap in their dispersion relation. pNIPAAm-based grating with a period around 280 nm was prepared by using photo-crosslinkable terpolymer and laser interference lithography and it was brought in contact with water. The temperature induced swelling and collapse of pNIPAAm hydrogel grating strongly modulates its refractive index (Δn~0.1) which leads to the reversible opening and closing of a plasmonic bandgap. The experiments demonstrate partial opening of a bandgap with the width of 12 nm at wavelength around 800 nm where SPR exhibited the spectral width of about 75 nm.