Coherent beam combining and phase noise measurements of ytterbium fiber amplifiers

Phase noise characterizatian of a 10-W Yb fiber amplifier is presented, and we demonstrate phase locking of two fiber amplifiers with near-perfect fringe contrast at power levels of as much as 10 W per fiber. Coherent beam combining is maintained during the turn-on transient as well as in thermal steady-state operation. (C) 2004 Optical Society of America