摘要
We investigate optical force on a graphene-coated gain microparticle by adopting the Maxwell's stress tensor method.It is found that there exists a threshold gain in obtaining the Fano-profile optical force which indicates the reversal of optical pushing and pulling force. And giant pushing/pulling force can be achieved if the gain value of the material is in the proximity of the threshold gain. Our results show that the threshold gain is more sensitive to the relaxation time than to the Fermi energy of the graphene. We further study the optical force on larger microparticle to demonstrate the pulling force occurring at octupole resonance with small gain value and then it will appear at quadrupole resonance by increasing gain value. Our work provides an in-depth insight into the interaction between light and gain material and gives the additional degree of freedom to optical manipulation of microparticle.
作者
陈鸿莉
黄杨
Hong-Li Chen;Yang Huang(School of Science,Nantong University,Nantong 226019,China;School of Science,Jiangsu Provincial Research Center of Light Industrial Optoelectronic Engineering and Technology,Jiangnan University,Wuxi 214122,China)
基金
supported by the National Natural Science Foundation of China (Grant Nos. 11904184, 11847033, and 11704158)
the Natural Science Foundation of Jiangsu Province,China (Grant No. BK20170170)。