Optimization of single mode fibre sensors to detect organic vapours

The construction of single mode optical fibre (SMF) sensors to handle with volatile organic compounds (VOCs), has been optimized to operate at the third telecommunication window (1550 nm). The main motivation is to take advantage of the photonic devices used in telecommunication systems that makes easier sensors multiplexing. Moreover, the low transmission attenuation at that wavelength offers the possibility of remote sensing. The sensing materials used suffer reversible structural alterations in the presence of VOC, such as colour change, which are detectable with a photonic system. Following the Electrostatic Self Assembly method (ESAm), a nanostructure is constructed onto cleaved ended SMF, which is doped with a sensing material. The fabrication of this type of sensors was focused on multimode fibres (MMF) and in the visible spectral range (VIS) so far. The implementation has been adapted to SMF and to operate around 1550 nm, specifically, by easing the adsorption of the VOCs molecules. It has been observed that the sensing material affects the morphology of the nanostructures as well and so, to the sensors response. The devices implemented show a potential use in the identification of single and complex mixtures of VOCs.