Analysis of far-field patterns of microdisk resonators by the finite-difference time-domain method

The far-field patterns of microdisk resonators are analyzed by using the finite-difference time-domain (FDTD) method and the near-to-far field transformation. A brief summary of FDTD and details of the transformation in the cylindrical coordinate system are presented. Using FDTD, the wavelengths and Q values of the resonant modes are calculated from an impulse excitation. The steady-state field solutions are calculated from sinusoidal sources. The far-field patterns of an ideal microdisk are presented.