Modification of intrinsic refractive index optical fiber sensor via precise cladding removal and heterogeneous ZnO/Ag bi-layer coating

Modification of intrinsic refractive index optical fiber sensor via precise cladding removal and heterogeneous ZnO/Ag bi-layer coating

Miniaturized refractive index sensor by combination of nanostructure thin films as a transformer sensitive layer and optical fiber as a signal carrier offers great potential for identifying the environmental features and understanding the novel sensor concepts. The partially unclad and bi-layer zinc...

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Main Author: Samavati, Zahra
Format: Thesis
Language:English
Published: 2020
Subjects:
TP Chemical technology
Online Access:http://eprints.utm.my/id/eprint/92403/1/ZahraSamavatiP2020.pdf.pdf
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spelling my-utm-ep.924032021-09-28T07:34:00Z Modification of intrinsic refractive index optical fiber sensor via precise cladding removal and heterogeneous ZnO/Ag bi-layer coating 2020 Samavati, Zahra TP Chemical technology Miniaturized refractive index sensor by combination of nanostructure thin films as a transformer sensitive layer and optical fiber as a signal carrier offers great potential for identifying the environmental features and understanding the novel sensor concepts. The partially unclad and bi-layer zinc oxide (ZnO) or silver (Ag) coated multimode glass and polymer optical fiber as a simple and reliable intrinsic fiber sensor was proposed in this work to detect the ambient refractive index changes (saline and crude oil having various concentrations) using two broadband sources of infrared radiation and ultraviolet-visible. The removing process to partially unclad the polymer and glass fiber was carried out precisely using our proposed dynamic monitoring process to prevent any interruption on propagating light by occurrence of damage on the core surface. The ZnO as an outer sensitive layer had three configuration which was spherical nanoparticle, horizontally and vertically oriented nanorods deposited on discontinuous Ag layer using mixture of electroless, dip coating and low temperature hydrothermal techniques because solo deposition technique was not possible. Ag nano-island shape deposition made the transition of evanescent wave to external media possibly through this semi-reflectance structure. ZnO coating avoided the formation of oxygen deficit defects, inhibited aging problem and trapping measurand molecules through mechanical interlock phenomena which altered its optical characteristics and improved sensitivity of the sensor. The x-ray diffraction spectra demonstrate that the level of crystallinity was higher for vertically oriented ZnO compared to others. Using field emission scanning electron microscope images, the width or length of vertically and horizontally oriented ZnO nanorods was measured. This shift is independent with the contact media. However, deep level emission depends strongly on the concentration of the contacted media. The shift observed for nanoparticle. The performance of fabricated probe to detect saline concentration changes for glass fiber coated with vertically oriented ZnO nanorods/Ag when IR light source employed, was supreme compared to the other samples and was reported to be 255.4 nm/RIU and 314.2 dB/RIU for wavelength and intensity sensing respectively. The durable polymer fiber coated with vertically oriented ZnO/Ag nanorods showed the intensity and wavelength sensitivity of 146.2 dB/RIU and 78.5nm/RIU respectively in identifying the variation of crude oil from 0 to 100%. The optimum length of glass and polymer fiber probe for maximum sensitivity was obtained for 3 cm and 2 cm respectively. The precise production techniques together with comprehensive analysis of the sensing mechanism lead to a deeper understanding of the liquid refractive index behavior applicable in quality control in water resource and oil reservoir. 2020 Thesis http://eprints.utm.my/id/eprint/92403/ http://eprints.utm.my/id/eprint/92403/1/ZahraSamavatiP2020.pdf.pdf application/pdf en public http://dms.library.utm.my:8080/vital/access/manager/Repository/vital:138721 phd doctoral Universiti Teknologi Malaysia Faculty of Engineering - School of Chemical & Energy Engineering
institution Universiti Teknologi Malaysia
collection UTM Institutional Repository
language English
topic TP Chemical technology
spellingShingle TP Chemical technology
Samavati, Zahra
Modification of intrinsic refractive index optical fiber sensor via precise cladding removal and heterogeneous ZnO/Ag bi-layer coating
description Miniaturized refractive index sensor by combination of nanostructure thin films as a transformer sensitive layer and optical fiber as a signal carrier offers great potential for identifying the environmental features and understanding the novel sensor concepts. The partially unclad and bi-layer zinc oxide (ZnO) or silver (Ag) coated multimode glass and polymer optical fiber as a simple and reliable intrinsic fiber sensor was proposed in this work to detect the ambient refractive index changes (saline and crude oil having various concentrations) using two broadband sources of infrared radiation and ultraviolet-visible. The removing process to partially unclad the polymer and glass fiber was carried out precisely using our proposed dynamic monitoring process to prevent any interruption on propagating light by occurrence of damage on the core surface. The ZnO as an outer sensitive layer had three configuration which was spherical nanoparticle, horizontally and vertically oriented nanorods deposited on discontinuous Ag layer using mixture of electroless, dip coating and low temperature hydrothermal techniques because solo deposition technique was not possible. Ag nano-island shape deposition made the transition of evanescent wave to external media possibly through this semi-reflectance structure. ZnO coating avoided the formation of oxygen deficit defects, inhibited aging problem and trapping measurand molecules through mechanical interlock phenomena which altered its optical characteristics and improved sensitivity of the sensor. The x-ray diffraction spectra demonstrate that the level of crystallinity was higher for vertically oriented ZnO compared to others. Using field emission scanning electron microscope images, the width or length of vertically and horizontally oriented ZnO nanorods was measured. This shift is independent with the contact media. However, deep level emission depends strongly on the concentration of the contacted media. The shift observed for nanoparticle. The performance of fabricated probe to detect saline concentration changes for glass fiber coated with vertically oriented ZnO nanorods/Ag when IR light source employed, was supreme compared to the other samples and was reported to be 255.4 nm/RIU and 314.2 dB/RIU for wavelength and intensity sensing respectively. The durable polymer fiber coated with vertically oriented ZnO/Ag nanorods showed the intensity and wavelength sensitivity of 146.2 dB/RIU and 78.5nm/RIU respectively in identifying the variation of crude oil from 0 to 100%. The optimum length of glass and polymer fiber probe for maximum sensitivity was obtained for 3 cm and 2 cm respectively. The precise production techniques together with comprehensive analysis of the sensing mechanism lead to a deeper understanding of the liquid refractive index behavior applicable in quality control in water resource and oil reservoir.
format Thesis
qualification_name Doctor of Philosophy (PhD.)
qualification_level Doctorate
author Samavati, Zahra
author_facet Samavati, Zahra
author_sort Samavati, Zahra
title Modification of intrinsic refractive index optical fiber sensor via precise cladding removal and heterogeneous ZnO/Ag bi-layer coating
title_short Modification of intrinsic refractive index optical fiber sensor via precise cladding removal and heterogeneous ZnO/Ag bi-layer coating
title_full Modification of intrinsic refractive index optical fiber sensor via precise cladding removal and heterogeneous ZnO/Ag bi-layer coating
title_fullStr Modification of intrinsic refractive index optical fiber sensor via precise cladding removal and heterogeneous ZnO/Ag bi-layer coating
title_full_unstemmed Modification of intrinsic refractive index optical fiber sensor via precise cladding removal and heterogeneous ZnO/Ag bi-layer coating
title_sort modification of intrinsic refractive index optical fiber sensor via precise cladding removal and heterogeneous zno/ag bi-layer coating
granting_institution Universiti Teknologi Malaysia
granting_department Faculty of Engineering - School of Chemical & Energy Engineering
publishDate 2020
url http://eprints.utm.my/id/eprint/92403/1/ZahraSamavatiP2020.pdf.pdf
_version_ 1747818592658784256

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