Nano-textured POF Surfaces to Enhance the Sensitivity of Low Concentration HF Sensors

This paper describes the possibility of enhancing the sensitivity of plastic optical fiber (POF) sensors for hydrogen fluoride vapours through a surface treatment of the polymeric core, performed in low pressure plasma. These high sensitivity POF sensors are realized by removing the cladding and performing a plasma nanotexturing of the core surface using oxygen/argon plasma treatments; then a thin, SiO2-like layer is deposited onto the nanotextured fibres core. The SiO2-like layer reacts with the HF vapours modifying the fibre response in terms of light transmittance. The first results show how the nanotexturing permits to increase the sensor sensitivity even though the nanotexturing is critical to be optimised and controlled.