Abstract
We present a theoretical study of the characteristics of the nonlinear spin-orbital angular momentum coupling induced by second-harmonic generation in plasmonic and dielectric nanostructures made of centrosymmetric materials. In particular, the connection between the phase singularities and polarization helicities in the longitudinal components of the fundamental and second-harmonic optical fields and the scatterer symmetry properties are discussed. By in-depth comparison between the interaction of structured optical beams with plasmonic and dielectric nanostructures, we have found that all-dielectric and plasmonic nanostructures that exhibit magnetic and electric resonances have comparable second-harmonic conversion efficiency. In addition, mechanisms for second-harmonic enhancement for single and chiral clusters of scatterers are unveiled and the relationships between the content of optical angular momentum of the incident optical beams and the enhancement of nonlinear light scattering is discussed. In particular, we formulate a general angular momenta conservation law for the nonlinear spin-orbital angular momentum interaction, which includes the quasi-angular-momentum of chiral structures with different-order rotational symmetry. As a key conclusion of our study relevant to nanophotonics, we argue that all-dielectric nanostructures provide a more suitable platform to investigate experimentally the nonlinear interaction between spin and orbital angular momenta, as compared to plasmonic ones, chiefly due to their narrower resonance peaks, lower intrinsic losses, and higher sustainable optical power.
Recommended Citation
X. Y. Xiong et al., "Mixing Of Spin And Orbital Angular Momenta Via Second-harmonic Generation In Plasmonic And Dielectric Chiral Nanostructures," Physical Review B, vol. 95, no. 16, article no. 165432, American Physical Society, Apr 2017.
The definitive version is available at https://doi.org/10.1103/PhysRevB.95.165432
Department(s)
Electrical and Computer Engineering
International Standard Serial Number (ISSN)
2469-9969; 2469-9950
Document Type
Article - Journal
Document Version
Final Version
File Type
text
Language(s)
English
Rights
© 2024 American Physical Society, All rights reserved.
Publication Date
19 Apr 2017
Comments
Horizon 2020 Framework Programme, Grant 648328