Open AccessDesign of ultra-sensitive biosensor applying surface plasmon resonance to a triangular resonator
Author(s) -
Geum-Yoon Oh,
Tae-Kyeong Lee,
Hong-Seung Kim,
Doo Gun Kim,
YoungWan Choi
Publication year - 2012
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.20.019067
Subject(s) - resonator , refractive index , surface plasmon resonance , optics , materials science , surface plasmon , biosensor , total internal reflection , free spectral range , resonance (particle physics) , plasmon , sensitivity (control systems) , optoelectronics , physics , nanotechnology , particle physics , electronic engineering , nanoparticle , engineering
We propose an ultra-sensitive integrated photonic sensor structure using an InP-based triangular resonator, in which a surface plasmon resonance (SPR) gold film is applied on a total internal reflection mirror. We have analyzed and optimized the triangular resonator sensor structure with an extremely small SPR mirror sensing area of 3.3 × 0.35 μm2. Due to the large phase shift in the SPR mirror, a significantly enhanced sensitivity of 930 nm/RIU (refractive index unit) and the maximum peak shift of half free spectral range have been obtained at the SPR angle of 24.125° with Au thickness of 33.4 nm for the change of the refractive index Δn = 1x10(-3). This value is larger than the previous largest value in micro resonator-type biosensors. Moreover, the proposed triangular resonator sensor can be easily made in a micro structure with optical source integration.