Whispering gallery modes of an open hemispherical image dielectric resonator

New results of theoretical and experimental investigation of an open hemispherical image dielectric resonator (HIDR) with whispering gallery modes (WGM) are presented The dependences of the WGM complex resonator frequencies on resonator parameters have been studied by the integral equation method. The dependences of the delay factor and Q-factor of HIDR WGM on resonator parameters and wavelength have been calculated numerically. It is shown that the WGM spectrum density of HIDR is smaller than that of a dielectric sphere. It is discovered that the dependence of the Q-factor of an open dielectric resonator WGM on the polar index has a maximum. (C) 1999 John Wiley & Sons, Inc. Microwave Opt Technol Lett 21: 252-257, 1999.