Ammonia sensing using a fibre optic long period grating with a porous nanostructured coating formed from silica nanospheres

Korposh, Sergiy; Batty, W.; Kodaira, S.; Lee, S.-W.; James, Stephen W.; Topliss, S. M.; Tatam, Ralph P.

doi:10.1117/12.866326

Cited by 5 publications

(7 citation statements)

References 3 publications

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“…Sol-gel coatings of SiO 2 and TiO 2 have been deposited onto LPGs, revealing a gain of approximately 2 in the sensitivity to external RI, with the higher index TiO 2 coating offering the larger response (up to 1067.15 nm/RIU). The authors noted that the higher the ind equivalent un infusion of a deposited usin significantly b sensing of am sensor 13 . The required to o mesoporous c EXPERIME An LPG of (Fibercore SM illuminating t period was se turning point, transmission fibre, and by When the uncoated 100 μm period LPG with a period of was immersed into water (RI=1.323), a blue shift of the LP 0,20 resonance band of 3 nm was observed.…”

Section: Introductionmentioning

confidence: 98%

Refractive index sensitivity of fibre optic long period gratings with SiO 2 nanoparticle based mesoporous coatings

et al. 2011

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A fibre optic long period grating (LPG) with a nano-assembled mesoporous coating of alternate layers of poly (allylamine hydrochloride) (PAH) and SiO 2 nanospheres was used for the development of a fibre-optic refractometer. PAH/SiO 2 films of different thickness have been deposited onto LPG in order to study the effect of the film thickness on sensor performance. The device showed a sensitivity of 1927 nm/RIU over a RI range of 1.3233-1.4906.

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Section: Introductionmentioning

confidence: 98%

Refractive index sensitivity of fibre optic long period gratings with SiO 2 nanoparticle based mesoporous coatings

et al. 2011

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“…The initially low RI of the mesoporous coating, 1.2, was increased significantly by the chemical infusion, resulting in a large change in the LPG's transmission spectrum. Additionally, the sensing of ammonia in aqueous solution was used as an example to demonstrate the sensing principle of the LPG sensor [28]. SiO 2 NPs are commercially available with a range of diameters from 10 to 100 nm and their surface charge is selectable [27].…”

Section: Introductionmentioning

confidence: 99%

Refractive index sensitivity of fibre-optic long period gratings coated with SiO₂nanoparticle mesoporous thin films

Korposh

Lee

James

et al. 2011

Meas. Sci. Technol.

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A fibre-optic refractive index sensor based on a long period grating (LPG) with a nanoassembled mesoporous coating of alternate layers of poly(allylamine hydrochloride) (PAH) and SiO2 nanospheres was demonstrated. PAH/SiO2 coatings of different thicknesses were deposited onto an LPG operating near its phase matching turning point in order to study the effect of the film thickness and porosity on sensor performance. Three aqueous solutions of ethanol, glucose and sucrose of different concentrations were used to allow characterization of the refractive index (RI) over a wide RI range (1.3330–1.4906). The device showed a high sensitivity (1927 nm/refractive index unit) to RI changes with a response time less than 2 s. In particular, the current study suggested that the low RI of the mesoporous film, 1.20 at 633 nm, facilitates the measurement of external indices higher than that of the cladding, extending the range of operation of LPG-based RI sensors. The ability of this device to monitor, in real time, RI changes during a dilution process is demonstrated and discussed.

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“…This is a result of the dependence of the phase matching condition upon the effective index of the cladding mode. This has been exploited widely to demonstrate LPG based refractometers [29], and to investigate the use of LPGs as species specific chemical sensors via the deposition of thin films of materials that displayed an analyte induced refractive index change [29,30,31,32].…”

Section: Optical Fibre Lpgsmentioning

confidence: 99%

“…Figure 5 shows the TS of an LPG with a grating period of 111 m measured in a bR solution (12 mg/mL) before and after exposure to actinic light (532 nm). The period of the LPG was chosen such that sensor operated at phase matching turning point, where 2 nd attenuation band (centred at 840 nm), corresponding to the coupling light from the core mode to LP021, is well developed [30]. The change of the RI of the bR solution induced by the actinic light led to an increase of the attenuation (12 %) at 840 nm and caused a 0.7 nm blue wavelength shift of the 1 st attenuation band (centred at 680 nm) that corresponded to the coupling to LP019, Figure 5.…”

Section: Lpgmentioning

confidence: 99%

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All-optical switching based on optical fibre long period gratings modified bacteriorhodopsin

Korposh

James

Partridge

et al. 2018

Optics & Laser Technology

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All-optical switching using an optical fibre long-period gating (LPG) modified with bacteriorhodopsin (bR) is demonstrated. The switching process is based on the photo-induced RI change of bR, which in turn changes the phase matching conditions of the mode coupling by the LPG, leading to modulation of the propagating light. The effect was studied with an LPG immersed into a bR solution and with LPGs coated with the bR films, deposited onto the LPGs using the layer-by-layer electrostatic self-assembly (LbL) method. The dependence of the all-optical switching efficiency upon the concentration of the bR solution and on the grating period of the LPG was also studied. In addition, an in-fibre Mach-Zehnder interferometer (MZI) composed of a cascaded LPG pair separated by 30 mm and modified with bR was used to enhance the wavelength range of all-optical switching. The switching wavelength is determined by the grating period of the LPG. Switching efficiencies of 16 % and 35% were observed when an LPG and an MZI were immersed into bR solutions, respectively. The switching time for devices coated with bR-films was within 1s, 10 times faster than that observed for devices immersed into bR solution.

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Ammonia sensing using a fibre optic long period grating with a porous nanostructured coating formed from silica nanospheres

Cited by 5 publications

References 3 publications

Refractive index sensitivity of fibre optic long period gratings with SiO 2 nanoparticle based mesoporous coatings

Refractive index sensitivity of fibre optic long period gratings with SiO 2 nanoparticle based mesoporous coatings

Refractive index sensitivity of fibre-optic long period gratings coated with SiO₂nanoparticle mesoporous thin films

All-optical switching based on optical fibre long period gratings modified bacteriorhodopsin

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Ammonia sensing using a fibre optic long period grating with a porous nanostructured coating formed from silica nanospheres

Cited by 5 publications

References 3 publications

Refractive index sensitivity of fibre optic long period gratings with SiO 2 nanoparticle based mesoporous coatings

Refractive index sensitivity of fibre optic long period gratings with SiO 2 nanoparticle based mesoporous coatings

Refractive index sensitivity of fibre-optic long period gratings coated with SiO2nanoparticle mesoporous thin films

All-optical switching based on optical fibre long period gratings modified bacteriorhodopsin

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Refractive index sensitivity of fibre-optic long period gratings coated with SiO₂nanoparticle mesoporous thin films