摘要
Relativistic electrons moving over a periodic metal grating can lead to an intriguing emission of light,known as Smith–Purcell radiation[SPR],the precursor of the free-electron laser.The speed of light plays a critical role in the far-field emission spectrum.Inspired by this photonic SPR,here we experimentally demonstrate a photoacoustic phased array using laser-induced shock waves.We observe acoustic radiation spectrum in the far field,perfectly predicted by a universal theory for the SPR.This scheme provides a tool to control the acoustic radiation in the near field,paving the way toward coherent acoustic wave generation and microstructure metrology.
作者
沈冬屹
赵国林
陈险峰
万文杰
Dongyi Shen;Guolin Zhao;Xianfeng Chen;Wenjie Wan(School of Physics and Astronomy,Shanghai Jiao Tong University,Shanghai 200240,China;University of Michigan-Shanghai Jiao Tong University Joint Institute,Shanghai Jiao Tong University,Shanghai 200240,China)
基金
supported by the National Natural Science Foundation of China(Nos.92050113 and 11674228)
the National Key Research and Development Program of China(Nos.2016YFA0302500 and 2017YFA0303700)
the Shanghai MEC Scientific Innovation Program(No.E00075)。
