title: Phase controlled beam combining with nonlinear frequency conversion.
abstract: A phase controlled beam combining via nonlinear optical conversion is proposed and demonstrated. This process involves the combining of the fields at the second harmonic frequency generated by non-collinear input fields. The arrangement of the excitation configuration allows the generated second-harmonic light waves to propagate collinearly, with phases coherently correlated. The manipulation of the conversion efficiency is then possible with the phase control of the input fields. The combined second-harmonic fields are shown to be conveniently and robustly variable from zero to a maximum value that greatly exceeds the second-harmonic field generated by a single laser beam. By using a self-adaptive control algorithm, it is possible to optimize the output without prior knowledge on each beamlet property. Either the second-harmonic output beam profile or the total second-harmonic output power can be optimized with the control algorithm.
authors.affiliation: State Key Laboratory of Optoelectronic Materials and Technologies, Sun Yat-sen University, Guangzhou 510275, China.
authors.forename: Peiqing
authors.initials: P
authors.lastname: Zhang
authors.forename: Yefeng
authors.initials: Y
authors.lastname: Guan
authors.forename: Xiangsheng
authors.initials: X
authors.lastname: Xie
authors.forename: Jianying
authors.initials: J
authors.lastname: Zhou
authors.forename: Li
authors.initials: L
authors.lastname: Yan
authors.forename: Kam Sing
authors.initials: KS
authors.lastname: Wong