Coherent polarization beam combining of four fiber amplifiers in 100 ns pulsed-regime

We demonstrate the coherent polarization beam combining (CPBC) of four polarization-maintained fiber amplifiers in 100 ns-pulse regime using single frequency dithering technique for the first time. Experimental results reveal that phase noise of each amplifier chain can be effectively suppressed. The combining efficiency of the CPBC system is 92% and the residual phase error is less than λ/20. The intensity profile of the coherently polarization combined beam is steady for long time observation without degradation of the beam quality.

► Coherent polarization beam combining of four pulsed fiber amplifiers is presented. ► The system can be with high efficiency (92%) without degrading the beam quality. ► The single frequency dithering technique in pulse-regime is demonstrated. ► The residual phase error of the phase control can be less than λ/20.