A low cost and reliable fiber optic ethanol sensor based on nano-sized SnO2

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 μm. The response time of the purposed sensor was found to be about 10 s for 1000 ppm ethanol concentration.