LAUSR

ABSTRACT A fibre-based Mach–Zehnder (MZ) temperature sensor based on an ultra-long polymer waveguide integrated in an open-cavity multimode optical fibre is presented and analysed. A two-photon polymerization method was used to fabricate the polymer waveguide in the centre of the open-cavity. The air cavity and polymer waveguide constitute the reference arm and the sensing arm of the interferometer. Measurements show that the temperature sensitivity of the sensor can reach up to –205 pm/°C owing to the high thermo-optical coefficient of the polymer waveguide. We believe that the proposed sensor could have useful applications in biomedicine, environmental science, and other industries owing to its high sensitivity, biocompatibility, and good stability.