ANALYSIS OF PROPAGATION CHARACTERISTICS OF WHISPERING-GALLERY MODES IN A DIELECTRIC DISK OR A CURVED RECTANGULAR DIELECTRIC WAVE-GUIDE

The finite-element method is applied for the analysis of whispering ga llery modes in curved optical waveguides. Numerical examples on the wh ispering gallery modes in a dielectric disk with rough boundaries are given. We also demonstrate that the whispering gallery modes and the n ormal guided modes in a curved rectangular dielectric waveguide are an alyzed consistently with our method and that the normal guided mode ap proaches the whispering gallery mode with an increase of waveguide wid th. Based on the analysis, the minimum width of the rectangular wavegu ide to support a whispering gallery mode is evaluated.