Photonics Research Group Home
Ghent University Journals/Proceedings
About People Research Publications Education Services


Publication detail

Authors: Y. Liang, M. Zhao, Z. Wu, G. Morthier
Title: Investigation of Grating-Assisted Trimodal Interferometer Biosensors Based on a Polymer Platform
Format: International Journal
Publication date: 5/2018
Journal/Conference/Book: Sensors
Editor/Publisher: MDPI , 
Volume(Issue): 18 p.9 pages
DOI: 10.3390/s18051502
Citations: 10 ( - last update: 19/5/2024)
3 (OpenCitations - last update: 19/4/2024)
Look up on Google Scholar
Download: Download this Publication (1.9MB) (1.9MB)


A grating-assisted trimodal interferometer biosensor is proposed and numerically analyzed.
A long period grating coupler, for adjusting the power between the fundamental mode and the second
higher order mode, is investigated, and is shown to act as a conventional directional coupler for
adjusting the power between the two arms. The trimodal interferometer can achieve maximal fringe
visibility when the powers of the two modes are adjusted to the same value by the grating coupler,
which means that a better limit of detection can be expected. In addition, the second higher order
mode typically has a larger evanescent tail than the first higher order mode in bimodal interferometers,
resulting in a higher sensitivity of the trimodal interferometer. The influence of fabrication tolerances
on the performance of the designed interferometer is also investigated. The power difference between
the two modes shows inertia to the fill factor of the grating, but high sensitivity to the modulation
depth. Finally, a 2050 2/RIU (refractive index unit) sensitivity and 43 dB extinction ratio of the
output power are achieved.

Related Research Topics

Back to publication list