台柱型底座对微盘谐振器回音壁模式影响分析

In this paper, the impacts of the angle and the size of the truncated-cone pedestal on the characteristics of whispering gallery modes in microdisk resonators are analyzed. First, the structure and parameters of the calculation model are established. Then, the three-dimensional finite difference time domain method is used to calculate the impacts of the angel, the top radius and the height of the pedestal of a silicon nitride microdisk on the characteristics of whispering gallery modes. The simulation results show that the angle of the truncated-cone has no effect on the resonant wavelength of modes, and it will reduce the Q value of the modes only in the situation when the angle is greater than 60 degrees. When the top radius of pedestal is pretty large or its height is much small, the change of the resonant wavelength and the decrease of the Q value will be caused. In the fabrication of microdisk resonator, it should be ensured that the truncated-cone angle is small, the top radius of the pedestal is small, and its height is high enough.