A fiber etched cavity for microsphere whispering-gallery-mode excitation

In this paper, we demonstrate a whispering-gallery-mode microsphere resonator. The device is fabricated by fusion splicing of a section of no-core fiber with multi-mode fiber and single-mode fiber at its two ends. The open end of multimode fiber is etched to create an arc shaped cavity, with a microsphere glued at its bottom. The device has a Q-factor of 1.21 × 10
⁴
, is robust in structure and of low cost.