华南师范大学邓冬梅团队近日研究了对称蝶形高斯光束的可调自动聚焦和光捕获。该项研究成果发表在2025年6月18日出版的《物理评论A》杂志上。

研究组提出了一种自动聚焦光束，称为对称蝶形高斯光束（SBGB）。推导了其在自由空间中的解析表达式，系统分析了其传输特性。与对称艾里高斯光束和对称皮尔斯高斯光束相比，SBGB表现出卓越的突然自动聚焦能力和增强的粒子捕获能力。通过调整分布因子，SBGB可以产生双焦结构。有趣的是，引入二阶啁啾因子使两个焦点能够演变成正交的针状结构。 

通过调整二阶线性调频因子，可以灵活调整SBGB的焦点大小、焦点位置和强度。此外，研究组从理论上分析了SBGB的捕获特性，并探索了其焦点区域的捕获力分布。实验结果证实，双针状焦点可以稳定地捕获和操纵多个二氧化硅颗粒。凭借出色的自动对焦性能和独特的焦点结构，SBGB在光学操纵、生物医学研究和激光加工方面具有巨大的应用潜力。

附：英文原文

Title: Tunable autofocusing and optical trapping with symmetric butterfly Gaussian beams

Author: Yujie Wu, Zijing Zhang, Man Tao, Zhenhang Xu, Chuhong Zhuang, Zihan Liu, Zan Zhang, Weiting Wang, Hongwei Gong, Shigen Ouyang, Dongmei Deng

Issue&Volume: 2025/06/18

Abstract: We propose an autofocusing beam, named the symmetric butterfly Gaussian beam (SBGB). Its analytical expression in free space is derived, and its transmission characteristics are systematically analyzed. Compared to the symmetric Airy Gaussian beam and symmetric Pearcey Gaussian beam, the SBGB exhibits superior abruptly autofocusing capabilities and enhanced particle trapping abilities. By adjusting the distribution factors, the SBGB can generate a bifocal structure. Interestingly, introducing a second-order chirp factor enables the two focal spots to evolve into orthogonal needlelike structures. The focal size, focal position, and intensity of the SBGB can be flexibly adjusted by tuning the second-order chirp factor. Moreover, we theoretically analyze the trapping properties of the SBGB and explore the trapping force distributions in its focal regions. Experimental results verify that the dual needlelike focal points can stably trap and manipulate multiple silica particles. With outstanding autofocusing performance and unique focal structures, the SBGB holds great potential for applications in optical manipulation, biomedical research, and laser processing.

DOI: 10.1103/tfs1-gy3h

Source: https://journals.aps.org/pra/abstract/10.1103/tfs1-gy3h