近场光镊技术研究新进展

Recent advances in near field optical tweezers

光镊技术,又称光学捕获技术,它是利用光的辐射压力来捕获和操纵包括电介质颗粒、生物细胞及生物大分子在内的微小粒子的。近场光镊技术利用近场光学倏逝场随距离急剧衰减的特征,可显著地降低捕获粒子的尺寸,实现纳米捕获。追踪了近场光镊技术的最新进展,包括全内反射相干倏逝场、近场光学镀膜光纤探针尖、激光照明金属探针尖和聚焦倏逝场用于近场光学捕获,并对其进行了比较,分析了它们存在的主要问题和未来发展方向。

Optical tweezers, also known as optical trapping. They are to utilize light radiation pressure to trap and manipulate micro-particles including dielectric spheres, cells and biological macro-molecules. For near field optical tweezers, the nature that near field evanescent wave decays rapidly with the distance may result in a significant reduced trapping volume and thus achieve nano-particle trapping. New advances in near field optical tweezers respectively by coherent evanescent wave generated by total internal reflection, near field metal-coated fiber probe, laser illuminated metal probe and focused evanescent wave are introduced. The characteristics of each methods are compared. The main difficulties and prospect for further investigation are also discussed.