Spectral shift and Q-change of circular and square-shaped optical   microcavity modes due to periodic sidewall surface roughness
  Radiation loss and resonant frequency shift due to sidewall surface roughness of circular and square high-contrast microcavities are estimated and compared by using a boundary integral equations method. An effect of various harmonic components of the contour perturbation on the Whispering-Gallery (WG) modes in the circular microdisk and WG-like modes in the square microcavity is demonstrated. In both cases, contour deformations that are matched to the mode field pattern cause the most significant frequency detuning and Q-factor change. Favorably mode-matched deformations have been found, enabling one to manipulate the Q-factors of the microcavity modes. 
Svetlana V. Boriskina (1 and 2), Trevor M. Benson (1), Phillip Sewell   (1), Alexander I. Nosich (1 and 3) ((1) George Green...