Autofocusing and spreading of partially coherent Butterfly beams modulated by flat-topped factor in atmospheric turbulence

作者：Cheng, Ke^*; Zhu, Xinghua; Zhou, Yan; Yao, Na; Zhong, Xianqiong

来源：Optik, 2018, 172: 1123-1128.

DOI：10.1016/j.ijleo.2018.07.017

• Butterfly catastrophe
• Autofocusing
• Atmospheric turbulence

By transferring higher hierarchy Butterfly catastrophe to optical field, the autofocusing behavior and beam spreading of partially coherent Butterfly beams modulated by flat-topped factor in atmospheric turbulence are investigated, where the input power is fixed. In the process of autofocusing behavior the main lobe remains its location near origin, which is different from the movement of main lobe in a lower hierarchy Pearcey beam. The turbulence does not change the autofocusing behavior, but accelerates the decaying in side lobes of butterfly structure. A higher coherence length can lead to a more concentrated intensity at autofocusing plane. The analysis of beam spreading also indicates that there exist critical values of propagation distance of z(c). A smaller flat-topped factor tends to maintain a smaller spreading for z < z(c), while for z > z(c) the opposite case can be found. Angular spread decreases with an increasing of coherence length, and a smaller beam order shows a larger far field divergence angle. The study of partially coherent Butterfly beams in turbulence provides the possibility of the atmospheric laser communication by using higher-order catastrophe optical field.

• 出版日期2018
• 单位成都信息工程大学; 四川文理学院