Absorbance properties of gold coated fiber Bragg grating sensor for aqueous ethanol

Abstract

Optical Fiber Bragg Grating (FBG) is commonly deployed as a wavelength selective filter in telecommunication as well as to detect physical changes such as pressure, temperature and strain in sensing applications. This paper presents an investigation of FBG as a chemical sensor towards ethanol in aqueous solution. Telecommunication standard single mode FBGs were coated with different thicknesses of thin gold films via sputtering deposition method. The combination of Bragg gratings and gold film enhances the evanescent wave on the surface of the optical fiber. It was found that the FBG coated with 50 nm gold layer exhibits the strongest response towards water with varying concentrations of ethanol. The sensor shows 55% change in absorbance levels when the concentration of ethanol is increased from 0 to 99.7% in water.

Increased sensitivity of Au-Pd nanolayer on tapered optical fiber sensor for detecting aqueous Ethanol

“…In return, these changes cause a corresponding change to the absorbance spectrum of the tapered fiber sensor. This is similar with the other reported work on fiber optic based Ethanol sensors [20,26].…”

“…Ethanol is a commonly utilized chemical in various industries such as medical, food processing, beverages and even as a replacement fuel in automotives [19,20]. Ethanol has a high volatility and flammability that can be dangerous for humans and living organisms, thus making the sensing of Ethanol crucial and important [21].…”

Dynamic Response of Tapered Optical Multimode Fiber Coated with Carbon Nanotubes for Ethanol Sensing Application

“…In a tapered fiber, a higher fraction of evanescent wave field passes inside the cladding, which is sensitive to the physical environment of its’ surroundings [ 19 , 29 ]. The interaction between the CNT on the tapered fiber tip and different concentrations of ethanol [ 30 ] molecules transforms the optical properties of the CNT film, resulting in the response of the developed sensors towards ethanol.…”

Fabrication of Fiber Bragg Grating Coating with TiO2 Nanostructured Metal Oxide for Refractive Index Sensor

“…FBG was coated with different film thicknesses of gold by sputtering deposition technique and using it as a chemical sensor for ethanol in aqueous solution. It was found that the 50 nm gold film enhances the evanescent wave on the optical fiber surface and increases its sensitivity to detect ethanol with different concentrations [7].…”