title: Method for estimating gain coefficient spectrum of erbium-doped fiber based on net gain-loss measurement employing 4I(13/2) level pumping.
abstract: The method for estimating the gain coefficient spectrum of an erbium-doped fiber (EDF) is proposed and demonstrated experimentally. The method employs a net gain-loss measurement that uses the 4I(13/2) level pumping of the EDF and the McCumber relation. A formula used to obtain the quotient of the gain and loss coefficient from the net gain-loss measurement is derived to determine the parameter in the McCumber relation. It is confirmed that the gain coefficient spectrum of an EDF estimated with the method coincides with the value estimated using a conventional net gain-loss measurement that employs the 4I(11/2) level pumping. The method is successfully applied to an erbium/ytterbium-doped fiber, for which it is impossible to perform a conventional net gain-loss measurement with pumping at the 4I(11/2) level of erbium ions because of the absorption transition of ytterbium ions from 2F(7/2) to 2F(5/2) levels.
authors.forename: Hirotaka
authors.initials: H
authors.lastname: Ono
authors.forename: Makoto
authors.initials: M
authors.lastname: Yamada
authors.forename: Kentaro
authors.initials: K
authors.lastname: Ichii
authors.forename: Shoichiro
authors.initials: S
authors.lastname: Matsuo