Graphene-oxide coated LPGs for humidity sensing applications


In this paper, we report a highly effective relative humidity (RH) sensor implemented on graphene oxide (GO) coated long period grating (LPG). The GO nanocolloides bonded onto a cylindrical fibre cladding enables the LPG with strong evanescent waves to absorb more water molecules increasing its RH sensitivity. In an LPG, the phase matching condition occurs when a forward propagating core mode is coupled with the co-propagating lower order cladding modes generating evanescent waves to interact with the surrounding medium. This unique effect of LPGs can be more enhanced with multilayer GO deposition. There is an expansion of GO film with the absorption of more water molecules as RH increases. The absorption of water molecules on GO coating increases the conducting carrier (holes) density on it, thus decreasing the refractive index of GO film. The combined effect of increasing evanescent waves and modulated refractive index makes the GO coated LPGs as effective RH sensors. Our recently achieved results have shown the RH sensitivity of the GO coated LPG is about 0.01 dB/%RH. We have also investigated the effect on GO layer thickness, showing thicker layer increases the RH response of the LPG cladding mode resonances in lower wavelength region.

Publication DOI:
Divisions: College of Engineering & Physical Sciences > Aston Institute of Photonics Technology (AIPT)
College of Engineering & Physical Sciences
Funding Information: This project is supported by the UK Royal Society Newton Advanced Fellowship programme (NAF/R1/191072) and European Union Horizon 2020 Research and Innovation Staff Exchange (RISE) programme (No. 872049, IPN-Bio).
Additional Information: Copyright 2020 SPIE. One print or electronic copy may be made for personal use only. Systematic reproduction, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper are prohibited.
Uncontrolled Keywords: Graphene oxide deposition,Humidity sensing,Long period fibre gratings,Electronic, Optical and Magnetic Materials,Condensed Matter Physics,Computer Science Applications,Applied Mathematics,Electrical and Electronic Engineering
Publication ISSN: 1996-756X
Last Modified: 16 Jul 2024 07:21
Date Deposited: 12 Jan 2021 10:45
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Related URLs: http://www.scop ... tnerID=8YFLogxK (Scopus URL)
https://www.spi ... 365.short?SSO=1 (Publisher URL)
PURE Output Type: Conference article
Published Date: 2020-04-01
Accepted Date: 2020-04-01
Authors: Sahoo, Namita
Sun, Zhongyuan
Zhou, Kaiming (ORCID Profile 0000-0002-6011-1912)
Chen, Xianfeng
Tan, Yidong
Zhang, Lin (ORCID Profile 0000-0002-1691-5577)



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