https://www.selleckchem.com/pr....oducts/bay-1000394.h
In this paper, we demonstrate a simple capillary-based coupler with optical zigzag transmission to excite whispering-gallery modes (WGMs) in a passive deformed microcavity. The coupler is just composed sections of a single mode fiber, a microsphere and a capillary, while neither corrosion nor tapering process is necessary. Based on the ray optics model, we obtain the criterion between the cone-apex angle and capillary wall thickness for the zigzag beams to excite WGMs effectively. This proper cone-apex angle range can be obtained by