Whispering-gallery mode composite sensors for on-chip dynamic temperature monitoring

Whispering-gallery mode temperature microsensors have been demonstrated to have extremely high accuracy. Previous experiments have been limited to indirect sensor heating by externally heating the local environment. In this paper, we coated PDMS films directly onto an electrical resistive wire as sensors, allowing on-chip dynamic temperature measurement. The effects of sensor size are discussed and verified through an expansion of the current theory of WGM resonance shifts to include composite materials. Finally, the WGM sensor’s measurements are compared to the same measurements recorded by a thermocouple, demonstrating the great advantages of WGM sensors for on-chip real temperature monitoring.