Abstract

Confinement of photons in a dielectric microsphere is attracting current interest from a fundamental as well as an application point of view. According to the Lorenz-Mie theory, microspheres with diameters of a few microns show very narrow optical resonance modes, which are known as optical whispering gallery modes (WGMs).¹A very high quality factor (Q value) has been observed in various materials. If we can form three-dimensional or two-dimensional arrayed structures with spheres of identical size, we can obtain modes with the characteristics of extremely slow group velocity. Such modes can be regarded as photonic band modes resulting from the tight-binding coupling of WGMs. To realize the idea of tight- binding photonic modes, precise control of sphere size is crucial.

© 1998 Optical Society of America