具有贝塞尔分布的柱对称矢量光束的非线性调控研究

Cylindrical vector beams have aroused significant attention because of their widespread application prospects in super-resolution imaging, super-fine processing, optical micro-manipulation, etc. Recently, a new type of cylindrical vector beams are generated by introducing the nondiffraction character and self-reconstruction property of Bessel beams into traditional cylindrical vector beams. Such a new type of cylindrical vector beams exhibit the dual characteristics of cylindrical vector beams and Bessel beams and possess wider potential applications, so it is soon become the reseach hot spots all over the world. Here, we propose the generation methods, fundmental characteristics and nonlinear manipulation mechanism of new type of cylindrical vector beam with Bessel distribution. The research plan is as follows: ① Explore the new beam mode of cylindrical vector beam with Bessel distribution and experimently generate new type of cylindrical vector beams (radially (azimuthally) polarized Bessel beams, rotating Bessel beams and the new beam mode we previously explored). Meanwhile, the tight focusing characteristics and nondiffraction characteristics of certain novel vector beams will be studied. ②The new effects and their mechanism resulted from the interactions between corresponding parameters of optical fields (polarization state, angular momentum and spatial structure,etc) and Kerr nonlinear medium will be investigated. The nonlinear modulation law of the spin angular momentum,orbital angular momentum and energy flux distributions of the beams when nonlinear effects exist will be summarized. Corresponding research results can be used to provide some new ways in how to generate and control the transmission behaviours of the novel types of vector beams. In the meanwhile, corresponding results can also be used to provide theoretical basises in expanding applications scop of vector beams or designing new types of optical equipments.

柱对称矢量光束因在超分辨成像、超精细加工、光学微操控等领域的巨大应用前景而备受关注。近年来，人们将贝塞尔光束的无衍射自重建特性引入传统柱对称矢量光束，产生了新型柱对称矢量光束。该类光束兼具二者的多重特性，拥有更宽的应用范围，从而成为当前的研究热点。本项目拟开展具有贝塞尔分布的柱对称矢量光束的新模式及其产生方法，基本特性和非线性调控机理研究。拟开展的研究工作有：①探究具有贝塞尔分布的柱对称矢量光束新模式，并实验产生（径向）角向偏振贝塞尔矢量光束、旋转贝塞尔高斯光束和探究得到的新型柱对称矢量光束模式，分析其紧聚焦特性和无衍射特性；②探讨新型矢量光束的偏振态、角动量、空间结构与克尔非线性介质相互作用导致的新效应及其机理，掌握克尔非线性效应对光束自旋角动量、轨道角动量和能流分布的调制规律。研究成果可为发展新型矢量光束及其操控方法提供新途径，也为拓展矢量光束的应用范围或设计新型光学仪器提供理论依据。

柱对称矢量光束因在超分辨成像、超精细加工、光学微操控等领域的巨大应用前景而备受关注。近年来，人们将贝塞尔光束的无衍射自重建特性引入传统柱对称矢量光束，产生了新型柱对称矢量光束。该类光束兼具二者的多重特性，拥有更宽的应用范围，从而成为当前的研究热点。本项目提出开展具有贝塞尔分布的柱对称矢量光束的新模式及其产生方法，基本特性和与物质相互作用的研究。已经开展并完成的工作有：（1）通过求解矢量亥姆霍兹方程得到了贝塞尔高斯矢量光束的解析表达式，并基于此探讨了贝塞尔高斯矢量光束的一些模式及其模式分布特性；（2）基于分步傅里叶算法数值模拟研究了矢量涡旋贝塞尔高斯光束在自由空间及其在克尔非线性情况下的演化规律。分别研究了低能量输入和高能量输入情况下矢量涡旋贝塞尔高斯光束在Kerr非线性介质中的演化。重点研究了高能量输入情况下光束的演化情况，发现初始时光束的中心暗斑变大同时其光束总体尺寸逐渐变小，随后光束将分裂成丝变为若干亮斑，光束分裂产生的若干亮斑还与其附近的亮斑之间发生相互作用，从而可以观察到光丝的产生，湮灭，排斥，吸引等现象；（3）搭建了一套实验装置用于产生携带涡旋相位的飞秒贝塞尔光束，同时搭建了一套实时成像光路用于研究其与硅片等材料的相互作用，用携带涡旋相位的飞秒贝塞尔光束激光辐照硅片，在材料表面刻蚀形成了微米量级的环状，螺旋状损伤形貌，初步研究了相关参数对光束与材料相互作用的影响。