Fiber pigtailed thin wall capillary coupler for excitation of microsphere WGM resonator

Hanzheng Wang, Xinwei Lan, Jie Huang, Lei Yuan, Cheol-Woon Kim, Hai Xiao
2013 Optics Express  
In this paper, we demonstrate a fiber pigtailed thin wall capillary coupler for excitation of Whispering Gallery Modes (WGMs) of microsphere resonators. The coupler is made by fusion-splicing an optical fiber with a capillary tube and consequently etching the capillary wall to a thickness of a few microns. Light is coupled through the peripheral contact between inserted microsphere and the etched capillary wall. The coupling efficiency as a function of the wall thickness was studied
more » ... ly. WGM resonance with a Q-factor of 1.14 × 10 4 was observed using a borosilicate glass microsphere with a diameter of 71 μm. The coupler operates in the reflection mode and provides a robust mechanical support to the microsphere resonator. It is expected that the new coupler may find broad applications in sensors, optical filters and lasers.
doi:10.1364/oe.21.015834 pmid:23842369 fatcat:hd5g6q3n5jbzzeeasm6r7mvs7i