Active phase and polarization locking of a 1.4 kW fiber amplifier.
A three-stage Yb-fiber amplifier emitted 1.43 kW of single-mode power when seeded with a 25 GHz linewidth master oscillator (MO). The amplified output was polarization stabilized and phase locked using active heterodyne phase control. A low-power sample of the output beam was coherently combined to a second fiber amplifier with 90% visibility. The measured combining efficiency agreed with estimated decoherence effects from fiber nonlinearity, linewidth, and phase-locking accuracy. This is the highest-power fiber laser that has been coherently locked using any method that allows brightness scaling.
Goodno
Gregory D
GD
Northrop Grumman Aerospace Systems, One Space Park, R1-1184D, Redondo Beach, California 90278, USA*Corresponding author: gregory.goodno@ngc.com
McNaught
Stuart J
SJ
Rothenberg
Joshua E
JE
McComb
Timothy S
TS
Thielen
Peter A
PA
Wickham
Michael G
MG
Weber
Mark E
ME