A low cost reliable ethanol fiber-optic sensor based on nano size SnO2
S. Sharifpour Boushehri, S. M. Hosseini-Golgoo, M. H. Sheikhi
Abstract
An evanescent fiber optic gas sensor with a single-mode silica fiber, whose clad is modified using chemically sensitive nano-sized amorphous tin oxide, has been developed and successfully investigated to detect ethanol vapor. The cladding region was removed by means of wet chemical etching technique, and the sensitive layer was deposited using electron-beam evaporation method. The sensing characteristics of the sensor were recorded for different concentrations, ranging from 1000 to 20,000 ppm ethanol at room temperature on the telecommunication wavelength of 1.55 lm. The response time of the purposed sensor was found to be about 10 s for 1000 ppm ethanol concentration.
Investigation on Optical Properties of Bilayer Graphene Nanoribbons
M. Berahman, S. Sharifpour Boushehri, H. Nadgaran
Abstract:
Optical properties of α and β configuration of Zigzag and Armchair Bilayer Graphene Nanoribbons (BGNRs) have been investigated for longitude and transverse polarized of incident beam using Density functional Theory by considering local electric field. It is shown that broadening energy is a critical theoretical constant that should define properly in order to illustrate most important information on the interlayer transitions. Despite of that theoretical perspective, it is shown that depending on the width and edge symmetries, BGNRs could demonstrate various different optical absorption spectrums. These absorption spectra have obeyed different rules. These rules are defined, based on the edge symmetries of each BGNR. It is shown that in longitudinal polarization the inter sub-band transitions happen between the different parities of the wave function. However, in transverse direction, transitions are between the same parities. This rule is followed by Zigzag BGNRs. Armchair BGNRs, based on width symmetry show either similar characteristic to Zigzag BGNR or mono frequency spectrum. In addition, α configuration has slightly wider absorption region than β ones. However, both show almost similar behavior in region. These characteristics could be used as a tool in experimental investigations to scrutinize edge properties of samples.
Effects of post annealing temperature on optical properties and ethanol sensing of electron-beam evaporated tin oxide nano structures
S. Sharifpour Boushehri, S. M. Hosseini-Golgooa, M. H. Sheikhi
Abstract: Effects of post annealing temperature on absorption spectrum and ethanol sensing properties of electron-beam evaporated nano structure tin oxide in the wavelength range of 400 to 1100 nm was studied. It was observed that by increasing the post annealing temperature, SnO2 absorption increased and grains are agglomerated. In addition, sensitivity to ethanol vapor decreases due to reduction of surface area values.
Design and optimization of evanescent field fiber optic chemical sensor base on SnO2
S. Sharifpour Bousherhri,M. H. Sheikhi and S.M. Hosseini-Golgoo
Abstract- Evanescent field fiber optic with sensitive thin film of SnO2 has been considered as potential gas sensor. The Finite Difference –Beam propagation method (FD-BPM) is used as our numerical process and single mode fiber optic SMF-28 is used as based model. In the process of simulation, all data and constants have been considered by our own experimental work. We optimized our structure corresponding to sensitivity and power loss and represent the optimized structure.