Changes of the SNAP resonator shape owing to mode energy dissipation

The whispering gallery mode (WGM) optical microresonators formed on the optical fiber surface appear as a promising ultraprecise and ultralow loss technological platform (known as Surface Nanoscale Axial Photonics, SNAP) to create miniature optical devices including delay lines, signal processors, photonic sensors, optical frequency comb generators, etc. It is important to note that applications involving high intracavity power may face intense cavity heating and hence unwanted radius changes. Here we the heating effects in SNAP cavities both experimentally and numerically and reveal the changes in the mode structure induced by the heating due to whispering gallery mode energy dissipation.