Fine temperature measurement and fabrication of on-chip whispering-gallery mode micro-sensors

Whispering-Gallery mode based optical micro-devices have been demonstrated to have extremely high sensitivity to changes in local temperature owing to their high quality factors and frequency-based measurements. In this paper, we first examine different fabrication techniques for integrating whispering-gallery mode sensors directly onto heating components to realize on-chip in-situ dynamic temperature measurements and monitoring. The merits and drawbacks of each fabrication technique are discussed. Then, the capability of the fabricated on-chip micro-sensors to perform precise real-time thermal measurements was tested, and the findings are discussed. Finally, the advantages of such on-chip sensors are established through heat transfer analysis.