 Optical amplifier

A medium in which stimulated emission can increase an incident optical signal. Its unsaturated gain, saturation response and loss budget determine the propagation. A population balance with negative net gain instead describes absorption.

These are closely related to lasers, as they do a similar basic job: take a DC source as input and amplify light. Lasers just happen to use the input voltage to also generate the incoming light.

An optical amplifier is a device that amplifies an optical signal directly, without the need to convert it to an electrical signal first. It is a key component in fiber optic communication systems and is used to boost the strength of light signals over long distances, where signal attenuation can occur.