Open AccessSymmetric guided-mode resonance sensors in aqueous media with ultrahigh figure of merit
Author(s) -
Yi Zhou,
Xuesong Li,
Shuai Li,
Zhihe Guo,
Pan Zhang,
Junbo He,
Dongchen Wang,
Rongjun Zhang,
Ming Lu,
Shuyu Zhang,
Xiang Wu
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.27.034788
Subject(s) - figure of merit , laser linewidth , refractive index , materials science , optics , sensitivity (control systems) , optoelectronics , resonance (particle physics) , physics , laser , electronic engineering , particle physics , engineering
Optical sensors with a high figure of merit (FOM) for refractive index measurement can substantially enhance detection performance. For guided mode resonance (GMR) sensors, previous works mainly focused on the sensitivity enhancement rather than FOM optimization; therefore, the state-of-the-art FOM is limited within the range of 100. To address this, we propose a low-index, ultraviolet-curable resin (n = 1.344) to form a simple, stable, symmetric, GMR sensor, with enhanced sensitivity, narrowed resonant linewidth, and substantially improved FOM, in aqueous media. The influence of structural parameters was systematically investigated, and optimized FOM values as high as tens of thousands were obtained using numerical calculation. Using low-cost, nanoimprinting technology, we experimentally demonstrated a spectral linewidth as narrow as 56 pm, a bulk refractive index sensitivity of 233.35 nm / RIU, and a low detection limit 1.93 × 10 -6 , resulting in a FOM value up to 4200 (48 times typical GMR sensors). The proposed symmetric GMR sensor exhibits great potential in a variety of applications, including label-free biosensing, bio-imaging, and optical filters.