FIELD: engineering physics; laser radiation amplifying devices. SUBSTANCE: fiber light conductor of optical quantum amplifier is, essentially, fiber light conductor built up of core, light-guiding region, and envelope around them. Light-guiding region is doped with ions of rare-earth elements. Distance between core axis and closest point of light-guiding region meets definite relationship. Mean intensity of output signal radiation saturating fiber-optic quantum amplifier is increased without increasing threshold pumping power when amplifier is built around fiber light conductor doped with ions of rare-earth elements using three-level circuit arrangement. EFFECT: improved intensity of laser radiation. 2 dwg
