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 experimentally. WGM resonance with a Q-factor of 1.14 x 104 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.
National Science Foundation (U.S.)
- Microspheres,
- Optical fibers,
- Q factor measurement,
- Resonators,
- Thin walled structures,
- Whispering gallery modes, Broad application,
- Capillary wall,
- Coupling efficiency,
- Fusion splicing,
- Mechanical support,
- Microsphere resonators,
- Reflection modes,
- Wall thickness, Borosilicate glass
Available at: http://works.bepress.com/jie-huang/42/
The work was supported by National Science Foundation under the contract CMMI-1200787.