Whispering gallery mode resonators

Patent Granted Optical modes in a whispering gallery resonator are inherently lossy due to a mechanism similar to quantum tunneling. Strictly speaking, total internal reflection does not take place at a curved boundary between two distinct media, and light inside a whispering gallery resonator cannot be perfectly trapped, even in theoretically ideal conditions. Such a loss channel has been known from research on optical waveguide theory and is dubbed tunneling ray attenuation[28] in the field of fiber optics.