title: Coherent combining of a 4 kW, eight-element fiber amplifier array.
abstract: Commercial 0.5 kW Yb-doped fiber amplifiers have been characterized and found to be suitable for coherent beam combining. Eight such fiber amplifiers have been coherently combined in a tiled-aperture configuration with 78% combining efficiency and total output power of 4 kW. The power-in-the-bucket vertical beam quality of the combined output is 1.25 times diffraction limited at full power. The beam-combining performance is independent of output power.
authors.affiliation: Lincoln Laboratory, Massachusetts Institute of Technology, 244 Wood Street, Lexington, Massachusetts 02420, USA. chars@ll.mit.edu
authors.forename: C X
authors.initials: CX
authors.lastname: Yu
authors.forename: S J
authors.initials: SJ
authors.lastname: Augst
authors.forename: S M
authors.initials: SM
authors.lastname: Redmond
authors.forename: K C
authors.initials: KC
authors.lastname: Goldizen
authors.forename: D V
authors.initials: DV
authors.lastname: Murphy
authors.forename: A
authors.initials: A
authors.lastname: Sanchez
authors.forename: T Y
authors.initials: TY
authors.lastname: Fan