Mode selection for a whispering gallery mode resonator

Abstract

An original mode selection for a sapphire whispering gallery mode resonator (WGMR) is reported. A set of metallic lines are deposited directly on the top of the sapphire disk. The position and the width of these lines was chosen to modify the boundary conditions of the undesirable modes without affecting the main resonance. The efficiency of our mode selection method is experimentally demonstrated on a room temperature WGMR.