光镊是一门利用光的动量与物质相互作用产生光势阱效应以实现粒子捕获的重要技术, 该技术被广泛应用于纳米或微米级微粒的捕获及操控领域。当今技术和需求的发展对光镊系统的光束变换提出了更高的要求, 因此需要对捕获光源的光束进行整形, 获得光镊所需的光场分布。以激光光束整形的器件为主线, 分别介绍在光镊系统中使用棱镜、衍射光学元件、液晶空间光调制器、数字微镜器件、光纤等光学元件进行捕获光源光束整形的情况。列出了这些器件组成的典型整形光路, 以及近年来这些器件在光束整形方面的研究进展。同时还介绍了在捕获光源的整形设计中, 上述方法的各自特点及相应的捕获能力。

Optical tweezer is an important technique that utilizes the interaction between momentum of light and matter to produce light potentials and then realize particle trapping. Optical tweezer is widely used in the field of nano- or micron-scale particle capture and manipulation. The development of today′s technology and demands puts forward higher requirements for beam transformation of optical tweezers. Therefore, it is necessary to shape the light beam to obtain the required light field distribution of the optical tweezers. We follow laser beam shaping devices, and the applications of prism, diffractive optical elements, spatial light modulators, digital micro-mirror devices, optical fibers and other optical components in the optical tweezer system are introduced. Typical shaping optical paths of these devices are listed, and recent advances in beam shaping of these devices are presented. Characteristics of the methods mentioned above and their corresponding capture abilities in the shaping design of the capture light source are introduced as well.