Radiation loss and resonant frequency shift due to sidewall surface roughness of circular and square high-contrast microcavities are estimated and compared by use of 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.
© 2004 Optical Society of America
(130.3120) Integrated optics : Integrated optics devices
(140.4780) Lasers and laser optics : Optical resonators
(140.5960) Lasers and laser optics : Semiconductor lasers
(230.5750) Optical devices : Resonators
(240.5770) Optics at surfaces : Roughness
Svetlana V. Boriskina, Trevor M. Benson, Phillip Sewell, and Alexander I. Nosich, "Spectral shift and Q change of circular and square-shaped optical microcavity modes due to periodic sidewall surface roughness," J. Opt. Soc. Am. B 21, 1792-1796 (2004)