基于微结构光纤的自加速类贝塞尔光束的构建方法及其特性研究

This project aims to carry out construction method and characteristics research on a novel self-accelerating Bessel-like beam based on the optical fiber technology. We build the Bessel-like beam light filed to be an asymmetric high order mode by using the beam propagation characteristics in the fiber, and then we modulate the light field phase by using a special designed phase-modulated optical fiber. The profile of the modulated beam still has a similar light field distribution with the Bessel function, and the main lobe of the beam maintains non-obvious diffraction while a transverse acceleration can be obtained. Therefore this beam can propagate along a curved trajectory in the free space. This novel self-accelerating Bessel-like beam has transverse self-acceleration characteristics, therefore it can realize trapping and transporting the particles along a curved trajectory. This control mechanism can help a particular particle to bypass obstacles and move to the target location, which provide a very good application prospect for the chemical, biological and medical researching fields. The project aims to develop a new self-accelerating Bessel-like beam based on the optical fiber technology, obtaining Bessel-like beam generation method, building a physical model to simulate and calculate the propagation characteristics of the Bessel-like beam, achieving a new structure to construct the self-focusing beam by using the self-accelerating Bessel-like beam, providing a practical method for the self-accelerating beam family, developing a new method for the micro particle trapping and manipulating, laying a foundation for the key theory and widespread application of the Bessel beam.

本项目拟对基于微结构光纤及光纤组合技术的新型自加速类贝塞尔光束的构建方法及其光学特性开展研究。根据光束在光纤中的传播特性，利用光纤组合技术将光纤中传输的光场转换为非对称的高阶类贝塞尔光束，然后用一段特殊设计的相位调制光纤对该光场进行相位调制，调制后的光束横向截面仍然保持贝塞尔函数特性，但在保持其光束主瓣不明显衍射的前提下，获得横向加速度，使得光束能够在自由空间中沿着弯曲的路径传播。新型自加速类贝塞尔光束具有横向自加速特性，因而能够对处于其中的介质微粒实现三维捕获和沿弯曲路径输运的操作。本项目的目标是发展基于光纤技术的新型自加速类贝塞尔光束，获得自加速类贝塞尔光束的产生方法和传播特性的物理模型；提出利用自加速类贝塞尔光束构造自聚焦光束的新方法，为自加速光束家族增添一种新的实现形式；发展基于自加速类贝塞尔光束的微小物体捕获和操纵的新方法，为自加速类贝塞尔光束的广泛应用奠定关键性理论和应用基础。

本项目对基于微结构光纤及光纤组合技术的新型自加速类贝塞尔光束的构建方法及其光学特性开展了研究。根据光束在光纤中的传播特性，利用光纤组合技术将光纤中传输的光场转换为非对称的高阶类贝塞尔光束，然后用一段特殊设计的相位调制光纤对该光场进行相位调制，调制后的光束横向截面仍然保持贝塞尔函数特性，但在保持其光束主瓣不明显衍射的前提下，获得横向加速度，使得光束能够在自由空间中沿着弯曲的路径传播。新型自加速类贝塞尔光束具有横向自加速特性，因而能够对处于其中的介质微粒实现三维捕获和沿弯曲路径输运的操作。本项目发展了基于光纤技术的新型自加速类贝塞尔光束，获得了自加速类贝塞尔光束的产生方法和传播特性的物理模型；提出了利用自加速类贝塞尔光束构造自聚焦光束的新方法，为自加速光束家族增添一种新的实现形式；发展了基于自加速类贝塞尔光束的微小物体捕获和操纵的新方法，为自加速类贝塞尔光束的广泛应用奠定关键性理论和应用基础。项目取得的研究成果包括：获得了全光纤类贝塞尔光束的构建原理；提出了基于贝塞尔光束的双自加速光束的产生方法及粒子的曲线输运应用；实现了基于全光纤空心类贝塞尔光束的大尺寸粒子捕获。在该项目的资助下，申请人以第一或通讯作者发表了SCI收录论文32篇，国际会议论文3篇，申请发明专利20项，其中获得发明专利授权12项。