混合矢量偏振态对自动紧聚焦光束的焦场调控  

Focal Field Control of Tightly Autofocusing Beams with Hybrid Vector Polarizations

作　　者：黄铭帅 郭兆金 闫嘉龙 魏冰妍 李鹏[1] 刘圣[1] 赵建林[1] Huang Mingshuai;Guo Zhaojin;Yan Jialong;Wei Bingyan;Li Peng;Liu Sheng;Zhao Jianlin(Key Laboratory of Light-Field Manipulation and Information Acquisition of Ministry of Industry and Information Technology,Shaanci Key Laboratory of Optical Information Technology,School of Physical Science and Technology,Northwestern Polytechnical University,Xi'an 710129,Shaanxi,China)

机构地区：[1]西北工业大学物理科学与技术学院,光场调控与信息感知工业和信息化部重点实验室,陕西省光信息技术重点实验室,陕西西安710129

出　　处：《光学学报》2024年第13期271-277,共7页Acta Optica Sinica

基　　金：国家重点研发计划(2022YFA1404800);国家自然科学基金(12074312,12174309,12074313)。

摘　　要：自动紧聚焦光束可以大幅度增强焦场的纵向分量,具有“8字”型偏振投影的混合矢量光场则会有效地消除纵向场。二者结合能否达到中和的效果值得研究。本文研究了具有这种“8字”型偏振结构的自动紧聚焦光束的聚焦特性,分析了“8字”型偏振结构中偏振阶数、基矢以及交叉点偏振态等参量对焦场的影响。结果表明,焦场中心区域的横向偏振态与交叉点一致,由此可以控制焦场的横向偏振态;通过增加阶数可以削弱焦平面中的纵向场;“8字”型偏振结构可以使焦场中心处的纵向分量为零,离轴区域的纵向场则大幅减弱,其占比和峰值强度可由偏振阶数和交叉点控制。相关结果有望在光学成像、光操控、光学加工等领域得到应用。Objective The longitudinal components of the focal field can be greatly enhanced by the tightly autofocusing beams, and can be effectively eliminated by the hybrid vector light field with “8-type” polarization. Whether the combination of the two methods leads to sound results needs further research. In this paper, we study the focusing characteristics of the tightly autofocusing beams with “8-type” polarization to better manipulate the longitudinally polarization component of the focal field. Moreover, how the parameters of the “8-type” polarization affect the transversely polarization component is explored in this paper. We investigate the influence of the parameters, including polarization order, base vectors, and polarization of the cross point, on the focusing performance such as the size of the uniform polarization, the dependence of the transverse polarization with the input field, and the intensity control of the longitudinal field. This work has great application potential in optical imaging, optical manipulation, and optical machining.Methods Based on the Rayleigh-Sommerfeld vectorial diffraction theory described by Eq.(3), the propagation process of the tightly autofocusing beams with “8-type” polarization expressed by Eq.(2) is simulated by calculating the three polarization components of the optical field at different distances step by step. By changing the parameters of the “8-type” polarization given by Eq.(1), the focal field on the focal plane(z=35.18λ) is calculated, on which the effects of polarization order, base vectors, and cross-point polarization are analyzed.Results and Discussions Figure 1 shows the propagation processes of transverse and longitudinal components [Figs. 1(c1)and 1(c2)] and the total field [Fig. 1(c3)] of a tightly autofocusing beam of which the input intensity profile and polarization distribution are shown in Fig. 1(b). The projection trajectory of the “8-type” polarization on the Poincaré sphere is shown in Fig. 1(a). The intensity profiles of t

关 键 词：矢量光束 自聚焦光束 紧聚焦 纵向场 

分 类 号：O436[机械工程—光学工程]