Modal investigation of whispering gallery mode microtube resonators fabricated by laser machining

In this paper, we demonstrated the modal investigation of whispering gallery mode (WGM) microtube resonators fabricated by laser machining to characterize their dispersion property for Kerr frequency comb generation. We designed and fabricated microtube resonators by CO2 laser machining of fused quartz tubes. The finite element simulations were implemented to determine the quality factor with high accuracy and demonstrate the dispersion of the microtube resonators. The influences of outside diameters and side wall curvature radii of microtube resonators on dispersion are also demonstrated, which is of critical importance to the generation of Kerr frequency combs in a monolithic microresonator.