We demonstrate that,in a simple linearly-polarized plane wave,the optical pulling forces on nanoparticle clusters with gain can be induced by the Fano-like resonance.The numerical results based on the full-wave calcul...We demonstrate that,in a simple linearly-polarized plane wave,the optical pulling forces on nanoparticle clusters with gain can be induced by the Fano-like resonance.The numerical results based on the full-wave calculation show that the optical pulling forces can be attributed to the recoil forces for the nanoparticle clusters composed of dipolar nanoparticles with three different configurations.Interestingly,the recoil forces giving rise to optical pulling forces are exactly dominated by the coupling term between the electric and magnetic dipoles excited in the nanoparticle clusters,while other higherorder terms have a negligible contribution.In addition,the optical pulling force can be tailored by modulating the Fano-like resonance via either the particle size or the gain magnitude,offering an alternative freedom degree for optical manipulations of particle clusters.展开更多
In present work, we demonstrate that when a transverse magnetic （TM） Gaussian beam is incident to a magnetic metamaterial （MM） slab, it can be completely absorbed at a particular direction, resulting in a unidirec...In present work, we demonstrate that when a transverse magnetic （TM） Gaussian beam is incident to a magnetic metamaterial （MM） slab, it can be completely absorbed at a particular direction, resulting in a unidirectional perfect absorption. The unidirectionality is due to the time reversal symmetry （TRS） breaking nature of the MM; while the perfect absorbing effect is explained by the multiple scattering theory and the effective medium theory. By tuning the magnitude and the orientation of the external magnetic field, the working frequency can be adjusted and the unidirectionality can be reversed. Accordingly, we can design tun- able compact optical devices to achieve unidirectional perfect absorption.展开更多
基金Project supported by the Natural Science Foundation of Guangxi Province of China (Grant No.2021GXNSFDA196001)the National Natural Science Foundation of China (Grant Nos.12174076,12074084,and 12204117)+1 种基金Guangxi Science and Technology Project (Grant Nos.AD22080042 and AB21220052)Open Project of State Key Laboratory of Surface Physics in Fudan University (Grant No.KF2022_15)。
文摘We demonstrate that,in a simple linearly-polarized plane wave,the optical pulling forces on nanoparticle clusters with gain can be induced by the Fano-like resonance.The numerical results based on the full-wave calculation show that the optical pulling forces can be attributed to the recoil forces for the nanoparticle clusters composed of dipolar nanoparticles with three different configurations.Interestingly,the recoil forces giving rise to optical pulling forces are exactly dominated by the coupling term between the electric and magnetic dipoles excited in the nanoparticle clusters,while other higherorder terms have a negligible contribution.In addition,the optical pulling force can be tailored by modulating the Fano-like resonance via either the particle size or the gain magnitude,offering an alternative freedom degree for optical manipulations of particle clusters.
文摘In present work, we demonstrate that when a transverse magnetic （TM） Gaussian beam is incident to a magnetic metamaterial （MM） slab, it can be completely absorbed at a particular direction, resulting in a unidirectional perfect absorption. The unidirectionality is due to the time reversal symmetry （TRS） breaking nature of the MM; while the perfect absorbing effect is explained by the multiple scattering theory and the effective medium theory. By tuning the magnitude and the orientation of the external magnetic field, the working frequency can be adjusted and the unidirectionality can be reversed. Accordingly, we can design tun- able compact optical devices to achieve unidirectional perfect absorption.
