Tapered optical fiber devices with variable index coatings for modifying guide properties of the fundamental mode

摘要

An improved optical fiber device includes a length of optical fiber having a longitudinally tapered region for causing a portion of light signals guided by the fiber to emerge outside of the fiber. The tapered region is surrounded by a coating that operates on the portion of the light signals emerging from the fiber to modify their propagation properties. The tapered optical fiber device can be used in an optical fiber system which includes at least one source of light signals, wherein the optical fiber device is disposed in the path of light signals from the source.