Achieving maximum scattering circular dichroism through the excitation of anapole states within chiral Mie nanospheres

Abstract

The chirality-dependent asymmetric light-matter interaction can be enhanced using various artificial photonic structures as well as engineered incident field. Compared with chiral photonic structures, the engineered optical field is less explored and recently recognized as a new regime in tailoring light-matter interaction. In this work, we demonstrate that weakly chiral spheres can exhibit the maximum scattering circular dichroism (CD) by tailoring the incident field to construct chirality-sensitive anapole states. By considering the chiral terms radiated from Mie nanospheres as perturbation, a multiscattering model is established to predict the chiroptical Mie scattering response of these nanospheres. This model provides a specific guideline to tailor the incident field to realize the upper limit of the achievable scattering CD.

Enhanced Diffractive Circular Dichroism from Stereoscopic Plasmonic Molecule Array

“…However, the CD signals from natural molecules and materials are extremely weak. In recent years, many artificial nanostructures have been designed to obtain strong optical chiral response [ 3 , 4 , 5 , 6 , 7 , 8 ] for broad applications, including light circular polarizers [ 9 ], chiral nanomotors [ 10 ], asymmetric synthesis [ 11 ], chiral nonlinear optics [ 12 , 13 ], chiral molecule sensing [ 14 , 15 , 16 ], and so on. To enhance the chiroptical response, various structures have been designed, such as nano helix, split-ring resonator, and chiral holes [ 17 , 18 , 19 , 20 ].…”

Generation of tunable superchiral spot in metal-insulator-metal waveguide

“…Therefore, none of the above works has realized the superchiral spot, which is confined along all the spatial directions. This aim can be achieved by the designed nanostructrues, as reported in the previous works [10][11][12][13][14][15][16][17][18] , but the position of the superchiral spot is fixed, which introduces difficulty to immobilize chiral molecules in the superchiral region.…”

Mie Scattering Nanointerferometry for the Reconstruction of Tightly Focused Vector Fields by Polarization Decomposition

“…In the research field of the interaction between light and nanoscopic objects, the enhanced field in the near-field region can be obtained at certain frequencies, which is also known as optical resonance [1]. Assisted by optical resonance, many interesting properties of objects can be observed more easily, such as fluorescence emission [2,3], Raman scattering [4], bound states in the continuum (BIC) [5,6], anapole states [7,8], and nonlinear optical effects [9,10]. These resonances are closely related to the optical properties of the nanoparticles, which should be well-designed and fabricated as required.…”

“…On the other hand, studying the interaction mechanism between light and Mie particles will help us to explore new physical phenomena. For example, the upper limit of circular dichroism can be achieved at a specific frequency by using light excitation of anapole states in chiral nanospheres [7]. The nonlinear optical properties of a single Mie particle are used to detect the magnetic components of a light field with arbitrary electromagnetic structures [25].…”