title: Active coherent beam combination of two high-power single-frequency nanosecond fiber amplifiers.
abstract: We report on active coherent beam combining of two single-frequency nanosecond fiber amplifiers by using stochastic parallel gradient descent algorithm. Each fiber amplifier produces an average power of more than 100 W by using three-stage cascaded amplification. The two laser beams are actively phase-locked with a total average power of 215.8 W, producing ~8 ns pulses at 10 MHz repetition rate. The contrast of the far-field intensity pattern of the coherently combined beam is more than 83%.
authors.affiliation: College of Opticelectric Science and Engineering, National University of Defense Technology, Changsha, China.
authors.forename: Rongtao
authors.initials: R
authors.lastname: Su
authors.forename: Pu
authors.initials: P
authors.lastname: Zhou
authors.forename: Xiaolin
authors.initials: X
authors.lastname: Wang
authors.forename: Yanxing
authors.initials: Y
authors.lastname: Ma
authors.forename: Xiaojun
authors.initials: X
authors.lastname: Xu