3D printed microfiber waveguide in C-shaped fiber for temperature and air pressure measurement

In this study, we propose a microfiber waveguide for temperature and air pressure measurement. To improve mechanical strength of the sensor, a C-shaped fiber is sandwiches between two single mode fibers (SMFs) by fusion splice. The microfiber waveguide is 3D printed between two SMFs to connect two fiber cores by two-photon polymerization technology. Due to multimode property of this printed waveguide, a Mach-Zehnder interferometer (MZI) is obtained. This sensor exhibits a high temperature sensitivity of 361 pm/°C at 25°C to 45°C and a high air pressure sensitivity of 55 pm/kPa from 300hpa to 1000hpa. The MZI sensor features significant advantages such as small size, high stability, and easy fabrication, without the need for complex post-processing, showing great potential and broad application prospects in many sensing applications.