Integrated ultra-high-sensitivity temperature sensor based on asymmetric Mach-Zehnder interferometer and stress deformation of Aluminium-SiO2

This article proposes an integrated high-sensitivity temperature sensor based on SiO2-asymmetric Mach–Zehnder interferometer (AMZI) and thermal-expansion-induced stress of aluminum-SiO2. Mechanical analysis of this structure is carried out. The result shows that the SiO2 chip is compressed, and the waveguide length is decreased, leading to the central wavelength shift of the sensor. The sensitivity of the sensor can be customized by different arm lengths of the AMZI. The chip is fabricated using a standard planar lightwave circuit (PLC), and the aluminum alloy plate is glued to the chip using $\alpha $ -cyanaloc acrylic resin adhesive. The sensitivities of two sensors with different arm lengths are tested. The test results show the sensitivity reaches 6.86 and 54.2 nm $\cdot \text{K}^{-1}$ , respectively, which coincides with the theoretical analysis. With low cost and customizable sensitivity, this new device is applicable in many fields.