title: Fabrication, measurement, and application of 20/400 Yb-doped fiber.
abstract: We demonstrate an excellent 20/400 Yb-doped fiber in this work, from fabrication and measurement to application. To obtain good laser properties, some crucial parameters including the refractive index profile, geometrical morphology, and coating require precise controlling. Through a 7:1 pump combiner with six 120 W 915 nm fiber-coupled pump diode modules, a single all-fiber laser oscillator generated 500 W of continuous wave signal power at 1080 nm with 76.4% slope efficiency that is close to the theoretical limit. The signal power showed no evidence of roll-over and the highest output power was limited only by available pump power. This excellent 20/400 Yb-doped fiber could find application in higher-power fiber lasers.
authors.forename: Lei
authors.initials: L
authors.lastname: Liao
authors.forename: Yibo
authors.initials: Y
authors.lastname: Wang
authors.forename: Yingbin
authors.initials: Y
authors.lastname: Xing
authors.forename: Haiqing
authors.initials: H
authors.lastname: Li
authors.forename: Jinggang
authors.initials: J
authors.lastname: Peng
authors.forename: Nengli
authors.initials: N
authors.lastname: Dai
authors.forename: Jinyan
authors.initials: J
authors.lastname: Li