Ideal Kerker scattering by homogeneous spheres: the role of gain or loss

• Qingdong Yang,
• Weijin Chen,
• Yuntian Chen and
• Wei Liu

Beilstein J. Nanotechnol. 2022, 13, 828–835, doi:10.3762/bjnano.13.73

• . China College for Advanced Interdisciplinary Studies, National University of Defense Technology, Changsha, Hunan 410073, P. R. China 10.3762/bjnano.13.73 Abstract We investigate how the optical gain or loss (characterized by isotropic complex refractive indexes) influence the ideal Kerker scattering of

• exactly zero backward scattering. It was previously shown that, for non-magnetic homogeneous spheres with incident plane waves, either gain or loss prohibit ideal Kerker scattering, provided that only electric and magnetic multipoles of a specific order are present and contributions from other multipoles

• produce ideal Kerker scattering. Moreover, we further demonstrate that, when multipoles of different orders are simultaneously taken into consideration, loss or gain can serve as helpful rather than harmful contributing factors, for the elimination of backward scattering. Keywords: gain and loss; Kerker

High-contrast and reversible scattering switching via hybrid metal-dielectric metasurfaces

• Jonathan Ward,
• Khosro Zangeneh Kamali,
• Lei Xu,
• Guoquan Zhang,
• Andrey E. Miroshnichenko and
• Mohsen Rahmani

Beilstein J. Nanotechnol. 2018, 9, 460–467, doi:10.3762/bjnano.9.44

• during heating. All modes experience a drastic change around 1235 nm, where a clear interference between electric and magnetic modes (EQ, MQ, and ED, MD) takes place. Interestingly, after heating, around 1235 nm, EQ and MQ experience a comparable magnitude that enables Kerker scattering condition and

• , composed of silicon disk and gold bar lattices, with a reversible switching capability of the Kerker scattering condition. The tunability is achieved by the active control on the excitation and interference between the electric and magnetic resonances through heating the metasurface. It is shown that the

• metasurface based on the scattering properties of resonant nanoparticles and metasurfaces [44][45]. However, after heating the sample to 300 °C, most of the scattered field is in the forward direction, and the backward scattering is suppressed. High scattering directionality is achieved based on the Kerker