Simultaneous Measurement of Temperature and Pressure by Utilizing an Integrated Mach-Zehnder

A highly sensitive temperature and pressure sensor based on a cascade structure of an integrated Mach-Zehnder interferometer waveguide and an Fabry-Perot cavity is proposed and experimentally demonstrated. The waveguide is fabricated by the standard Planar Lightwave Circuit procedure, while the Fabry-Perot cavity is formed by a thin film layer made of a urethane-based UV-curable polymer. The ambient perturbations of temperature and pressure can be measured by monitoring the dip shifts of the Mach-Zehnder interference and the FP interference. The sensor can offer a high temperature sensitivity of ~0.317 nm/°C and a pressure sensitivity of -199.0 pm/KPa. Such a cascaded sensor is the first step to approach to a fully-integrated dual-parameter sensor, which has not been reported yet within the scope of our knowledge. The proposed sensing system has promising applications in various conditions, such as stress environment, liquid condition and solid building.