Gradient-induced long-range optical pulling force based on photonic band gap  

作　　者：Wenlong Lu Alexey V.Krasavin Sheng Lan Anatoly V.Zayats Qiaofeng Dai 

机构地区：[1]Guangdong Basic Research Center of Excellence for Structure and Fundamental Interactions of Matter,Guangdong Provincial Key Laboratory of Nanophotonic Functional Materials and Devices,School of Information and Optoelectronic Science and Engineering,South China Normal University,Guangzhou 510006,China [2]Department of Physics and London Centre for Nanotechnology,King’s College London,London WC2R 2LS,UK

出　　处：《Light(Science & Applications)》2024年第5期865-874,共10页光（科学与应用)（英文版）

基　　金：Q.D.thanks for the financial support from the Natural Science Foundation of Guangdong Province,China(2019A1515011578);Department of Science and Technology of Guangdong Province,China(2020B1212060067);A.K.and A.Z.work was supported by the ERC iCOMM project(789340).

摘　　要：Optical pulling provides a new degree of freedom in optical manipulation.It is generally believed that long-range optical pulling forces cannot be generated by the gradient of the incident field.Here,we theoretically propose and numerically demonstrate the realization of a long-range optical pulling force stemming from a self-induced gradient field in the manipulated object.In analogy to potential barriers in quantum tunnelling,we use a photonic band gap design in order to obtain the intensity gradients inside a manipulated object placed in a photonic crystal waveguide,thereby achieving a pulling force.Unlike the usual scattering-type optical pulling forces,the proposed gradient-field approach does not require precise elimination of the reflection from the manipulated objects.In particular,the Einstein-Laub formalism is applied to design this unconventional gradient force.The magnitude of the force can be enhanced by a factor of up to 50 at the optical resonance of the manipulated object in the waveguide,making it insensitive to absorption.The developed approach helps to break the limitation of scattering forces to obtain longrange optical pulling for manipulation and sorting of nanoparticles and other nano-objects.The developed principle of using the band gap to obtain a pulling force may also be applied to other types of waves,such as acoustic or water waves,which are important for numerous applications.

关 键 词：OPTICAL WAVEGUIDE SCATTERING 

分 类 号：O43[机械工程—光学工程]