Demonstration of an Ultra-Sensitive Temperature Sensor Using an Asymmetric Mach-Zehnder Interferometer

We present the design, fabrication and characterization of an on-chip, ultra-high sensitivity temperature sensor using asymmetric Mach-Zehnder interferometer (MZI) on silicon-on-insulator (SOI) platform. Both the group index and the sensitivity differences between two arms are considered for simultaneous sensitivity and linear range enhancement. The fabrication of the sensor only needs single lithography without introducing any high thermo-optic coefficient (TOC) materials. The experimental results demonstrate a sensitivity of 445 pm/°C from 27 °C to 67 °C, which is five times larger than a conventional all-silicon photonic temperature sensor (~80 pm/°C).