Open AccessImplementation and phase detection of dielectric-grating-coupled surface plasmon resonance sensor for backside incident light
Author(s) -
Wen−Kai Kuo,
Jaturon Tongpakpanang,
Ping-Hong Kuo,
ShengFeng Kuo
Publication year - 2019
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.27.003867
Subject(s) - materials science , optics , refractive index , surface plasmon resonance , optoelectronics , grating , surface plasmon , ray , dielectric , etching (microfabrication) , groove (engineering) , plasmon , nanotechnology , nanoparticle , layer (electronics) , physics , metallurgy
This paper proposes a design for a dielectric-grating-coupled surface plasmon resonance (SPR) sensor that can be fabricated using a low-cost nanoimprint process and exhibits a high phase detection sensitivity when light is incident on the backside of the sensor and does not pass through the analyte on the front-side of the sensor. A low-refractive-index material (mesoporous silica) is utilized to implement a reverse symmetric waveguide structure that can enhance electric-field strength on the sensor surface and improve detection sensitivity. A sol-gel method is used to fill the groove of the grating structure with a high-refractive-index material (titanium dioxide), and surface smoothness is improved via a flat silicon impression mold. The experimental results indicate that although the sensor device exhibits defects and non-smooth surface relief, phase detection sensitivity can still be achieved as high as 2 × 10 -5 RIU by using an electro-optic heterodyne interferometer.