Temperature sensitivity of silica micro-resonators

Qiulin Ma, Tobias Rossmann, Zhixiong Guo
2008 Journal of Physics D: Applied Physics  
Optical resonance shifts are measured against temperature changes for different silica beads ranging from 80 to 450 µm in diameter. A micro-bead is fabricated by hydrogen flame fusing the tip of a single mode silica fibre/taper, and coupled to a fibre taper of submicrometre diameter. The coupling system in whispering-gallery modes is placed in an insulated cell. The air in the cell is slowly heated up from room temperature to about 10 K higher, and red shifts of a resonance wavelength during
more » ... avelength during the heating process are recorded. Linear dependence of the wavelength shift versus the temperature rise is observed for all the tested micro-resonators. The measured sensitivity for beads greater than 200 µm in size closely matches the analytical value based on bulk material properties of silica thermal expansion and the thermo-optic effect. For smaller micro-beads, however, the measured sensitivity increases with shrinking bead size. The ultra-high resolution of such a kind of temperature micro-sensor and its potential applications are addressed.
doi:10.1088/0022-3727/41/24/245111 fatcat:crutyzsodneevfpebwjvkwzsha