AlN-on-sapphire microdisk resonators for precise on-chip temperature sensing

Photonic integrated circuit sensors can be used for precise sensing of the environment, offering the advantage of integration with fiber networks for remote and multiplexed sensor arrays. In this work, we examine the performance of aluminum nitride on sapphire microdisk mode resonators in an all-pass configuration. We discuss their potential as on-chip temperature sensors under fixed-frequency and frequency-scanning modes, demonstrating the latter can measure a 1 K temperature change with an uncertainty of ±5.1 mK over a temperature range of 25–55 °C.