A Mach-Zehnder interferometer-based High Sensitivity Temperature sensor for human body monitoring

Hyperthermia is a noticed tumor therapy method developed over recent years. In tumor hyperthermia, a real-time monitoring device for body temperature is required. In this work, a novel Mach-Zehnder interferometer-based temperature sensor is proposed and experimentally demonstrated. The sensing structure is formed by splicing a piece of single-mode fiber between two pieces of single-mode fibers with a core-offset. Beam propagation method is adopted to simulate output spectrum of the sensing structure. The simulated results indicate that the sensing structure with a core-offset value of 62.85 μm performed well, which provide the basis for the sensor fabrication. Temperature response of the sensor is measured by immersing it in water. During the experiment, wavelength of the interference valley increases progressively with temperature, and the temperature sensitivity is up to 8.962 nm/°C from 33 °C to 43 °C. Meanwhile, this sensor has the advantages of simple structure, miniaturization and excellent repeatability and stability.