Optical fibers and Amplifiers for Deployed Networks

An optical amplifier is a device that amplifies an optical signal directly, without the need to first convert it to an electrical signal. An optical amplifier may be thought of as a laser without an optical cavity, or one in which feedback from the cavity is suppressed. Optical amplifiers are important in optical communication and laser physics. An important practical goal is to develop an amplifier adequate for use as an optical repeater in the long distance fiberoptic cables which carry much of the world's telecommunication links.