title: Generation of dark hollow beam via coherent combination based on adaptive optics.
abstract: A novel method for generating a dark hollow beam (DHB) is proposed and studied both theoretically and experimentally. A coherent combination technique for laser arrays is implemented based on adaptive optics (AO). A beam arraying structure and an active segmented mirror are designed and described. Piston errors are extracted by a zero-order interference detection system with the help of a custom-made photo-detectors array. An algorithm called the extremum approach is adopted to calculate feedback control signals. A dynamic piston error is imported by LiNbO3to test the capability of the AO servo. In a closed loop the stable and clear DHB is obtained. The experimental results confirm the feasibility of the concept.
authors.affiliation: Laboratory on Adaptive Optics, Institute of Optics and Electronics, Chinese Academy of Sciences, Chengdu, Sichuan, China. Zhengyi_ioe@163.com
authors.forename: Yi
authors.initials: Y
authors.lastname: Zheng
authors.forename: Xiaohua
authors.initials: X
authors.lastname: Wang
authors.forename: Feng
authors.initials: F
authors.lastname: Shen
authors.forename: Xinyang
authors.initials: X
authors.lastname: Li
mesh_terms: D017076:Computer-Aided Design; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005240:Feasibility Studies; D005246:Feedback; D007834:Lasers; D007909:Lenses; D008029:Lighting / Q000295:instrumentation*