一维光纤相控阵多光束快速扫描  

High-Speed Multibeam Steering of One-Dimensional Optical Fiber Phased Array

作　　者：王晓斌 刘春波 刘如愿 张霖 曹阳 韩香娥 Wang Xiaobin;Liu Chunbo;Liu Ruyuan;Zhang Lin;Cao Yang;Han Xiang’e(School of Telecommunication Engineering,Xidian University,Xi'an,Shaanxi 710071,China;School of Physics and Optoelectronic Engineering,Xidian University,Xi'an,Shaanxi 710071,China)

机构地区：[1]西安电子科技大学通信工程学院,陕西西安710071 [2]西安电子科技大学物理与光电工程学院,陕西西安710071

出　　处：《中国激光》2021年第17期63-71,共9页Chinese Journal of Lasers

基　　金：国家自然科学基金(61401341,61905185);高等学校学科创新引智计划资助(B17035)。

摘　　要：针对激光束快速扫描需求,研究基于光纤相控阵的多光束扫描。采用"先校正后扫描"方式,利用高速铌酸锂相位调制器,基于随机并行梯度下降算法,研制了相位控制电路系统,构建了1×16路光纤相控阵原理实验系统,进行了光束相干合成与多光束扫描实验。测试结果表明,算法单次迭代时间不超过10μs,相干合成光束主瓣光强峰值旁瓣比达24.7 dB(理论极限26.4 dB),扫描范围与理论值吻合。该16路光纤相控阵系统在实现高质量相干合成的同时,还可实现500 kHz相干合成光束扫描。Objective Fast and accurate beam scanning is the key technology in free space laser application.An optical phased array(OPA)based on electro-optics or thermo-optics overcomes the limitation of mechanical steering and can achieve noninertial beam steering with flexible beam pointing.It has demonstrated applications in free-space laser,such as light detection and ranging(LIDAR),free-space optical(FSO)communication,and optical imaging.The spatial light modulator(SLM)and microelectromechanical mirror array(MEMS)have realized tens of kHz and 1-MHz beam steering,respectively.Chip-scale OPA can achieve ultrawide beam steering and it has been demonstrated at kHz to GHz.However,chip-scale OPA suffers serious loss and cannot be used in remote detection.The optical fiber phased array(OFPA)based on a lithium niobate(LiNbO_(3))phase modulator can achieve beam directional and fast steering at GHz while realizing high power laser synthesis output,but the phase noises make each beam phase fluctuate strongly,which seriously affects the output beam quality and cannot guarantee its steering angle accuracy.Compared with the coherent combination of high power fiber lasers,the fast beam steering of OFPA not only involves phase control compensation but also ensures the accuracy of beam steering angle and higher steering speed,which improves the difficulty of phase control.Methods Based on LiNbO_(3)phase modulators and the stochastic parallel gradient descent(SPGD)algorithm,the phase noises of 1×16channel OFPAs are compensated,and the multibeam fast steering is achieved by the"steering after correction"method.First,a narrow-linewidth(<200kHz at 1550nm)laser is divided into several sub-beams through the polarization-maintaining(PM)fiber splitters.After the modulation by the electro-optic phase modulators and power amplification by the fiber amplifiers,these sub-beams are outputted by the fiber array,which is arranged and combined by PM single-mode bare fiber.Second,pinhole samples of the on-axis far-field intensity with a silicon photod

关 键 词：激光光学 光纤相控阵 光纤激光 光束扫描 相干光束合成 相位调制器 

分 类 号：TN249[电子电信—物理电子学]