Integrating Interference and Resonance Effects in Microfiber Sensors for Simultaneous Pressure and Temperature Measurement

This study presents a novel sensor that combines air pressure and temperature measurement using dual-interference microfiber resonators. The sensor leverages intermode interference and the resonant ring resonance effects within the microfiber loop structure, enabling simultaneous demodulation of temperature and air pressure. We have developed a mathematical model that is closely monitored alongside the reflectance spectral structure. The sensor exhibits two distinct linear sensitivities for pressure and two different linear sensitivities for temperature, as revealed by our testing results. Specifically, microfiber mode interference demonstrates a temperature and pressure sensitivity of 160 pm/°C and 167 pm/kPa, respectively, while the ring resonance effect yields a temperature and pressure sensitivity of 132 pm/°C and 62 pm/kPa, respectively. The maximum temperature resolution stands at 0.025 °C, and the pressure resolution is 0.023 kPa. These findings are supported by the concept of a linear connection, which serves as the foundation of the transmission matrix and enables concurrent discrimination of air pressure and temperature. This sensor offers advantages due to its straightforward structure, high extinction ratio, superior electrical safety, and effective protection against electromagnetic interference.