Coherent beam combination of adaptive fiber laser array with tilt-tip and phase-locking control

• Published in: Chinese physics B Vol. 22; no. 2; pp. 265 - 270
• Main Author: 王雄 王小林 周朴 粟荣涛 耿超 李新阳 许晓军 舒柏宏
• Format: Journal Article
• Language: English
• Published: 01.02.2013
• Subjects: Adaptive control systems; Beams (radiation); Cameras; CMOS摄像头; Control systems; Controllers; Fiber lasers; Field programmable gate arrays; Laser arrays; 光纤准直器; 动态控制系统; 激光器阵列; 现场可编程门阵列; 相干合成; 自适应; 锁相控制
• ISSN: 1674-1056; 2058-3834; 1741-4199
• DOI: 10.1088/1674-1056/22/2/024206

We present an experimental study on tilt-tip（TT） and phase-locking（PL） control in a coherent beam combination（CBC） system of adaptive fiber laser array.The TT control is performed using the adaptive fiber-optics collimator（AFOC）,and the PL control is realized by the phase modulator（PM）.Cascaded and simultaneous controls of TT and PL using stochastic parallel gradient descent（SPGD） algorithm are investigated in this paper.Two-fiber-laser-,four-fiber-laser-,and six-fiber-laser-arrays are employed to study the TT and PL control.In the cascaded control system,only one high-speed CMOS camera is used to collect beam data and a computer is used as the controller.In a simultaneous control system one high-speed CMOS camera and one photonic detector（PD） are employed,and a computer and a control circuit based on field programmable gate array（FPGA） are used as the controllers.Experimental results reveal that both cascaded and simultaneous controls of TT using AFOC and PL using PM in fiber laser array are feasible and effective.Cascaded control is more effective in static control situation and simultaneous control can be applied to the dynamic control system directly.The control signals of simultaneous PL and TT disturb each other obviously and TT and PL control may compete with each other,so the control effect is limited.