Sensitization of an optical fiber methane sensor with graphene

We analyze the mechanism by which tin oxide can be utilized for the optical sensing of methane gas via surface adsorption and electromagnetic theory. Single-mode optical fibers with core diameters of 9 μm and cladding diameters of 12 μm were used. A 15 mm-long segment of each optical fiber was polished to the core via wheel side-polishing; the exposed fiber core areas were coated with graphene-doped tin oxide such that a novel graphene-based optical fiber methane sensor was fabricated. The experimental results show that the sensor exhibits excellent linear fitting and reproducibility, making it useful for the detection of low concentrations of methane.