As an important step towards integration of microspheres in compact functional photonics devices, we demonstrate direct efficient coupling of light in and out of high-Q whispering- gallery (WG) modes in silica microspheres using angle- polished single mode fibers. Based on this principle, we present a 1-inch fiber-pigtailed microsphere module that can be used for fiber-optic applications, and a fiber-coupled erbium-doped microsphere laser at 1.55 micrometers . In addition, we report preliminary data on the intensity modulation based on high-Q WG modes in a lithium niobate sphere. We also demonstrate a novel geometry WG-mode optical microcavity that combines Q approximately 107, typical for microspheres, with few-nanometer mode spacing either available in lower quality factor Q approximately 104 microfabricated planar rings.© (2000) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.