Thulium-doped fiber amplifier using pump light for improving conversion efficiency in a S-band

Abstract

An optical fiber amplifier with a high conversion efficiency, which is capable of using the pump light in the wavelength band that can be emitted by the laser diode, is formed by an amplification optical fiber containing thulium at least in a core, to which a signal light is to be entered, and a pump light input unit configured to enter at least one pump light with a wavelength in a range of 1320-1520 nm, or more preferably 1320-1480 nm, into the amplification optical amplifier.

Dependencies are inferred from the claim text.