title: Adaptive conversion of a high-order mode beam into a near-diffraction-limited beam.
abstract: We present a new method for efficiently transforming a high-order mode beam into a nearly Gaussian beam with much higher beam quality. The method is based on modulation of phases of different lobes by stochastic parallel gradient descent algorithm and coherent addition after phase flattening. We demonstrate the method by transforming an LP11 mode into a nearly Gaussian beam. The experimental results reveal that the power in the diffraction-limited bucket in the far field is increased by more than a factor of 1.5.
authors.affiliation: College of Opto-Electronic Science and Engineering, National University of Defense Technology, Changsha, Hunan, China.
authors.forename: Haichuan
authors.initials: H
authors.lastname: Zhao
authors.forename: Xiaolin
authors.initials: X
authors.lastname: Wang
authors.forename: Haotong
authors.initials: H
authors.lastname: Ma
authors.forename: Pu
authors.initials: P
authors.lastname: Zhou
authors.forename: Yanxing
authors.initials: Y
authors.lastname: Ma
authors.forename: Xiaojun
authors.initials: X
authors.lastname: Xu
authors.forename: Yijun
authors.initials: Y
authors.lastname: Zhao