Selective magnetic responses of silicon nanoparticles modulated by waveguide structures

Area of Science:

• Nano-optics
• Plasmonics
• Nanophotonics

Background:

• High-refractive-index nanoparticles (NPs), like silicon NPs, are crucial for optical frequency magnetic field interactions.
• Substrate interactions, especially with waveguide structures, significantly influence NP optical responses but are understudied.
• Metal-dielectric waveguides (MDWs) offer polarization-dependent modulation of NP magnetic resonance.

Purpose of the Study:

• To propose and investigate a selective magnetic coupling system using a silicon NP on an MDW.
• To explore the polarization dependence of magnetic resonance induced by MDW modes (TE and TM).
• To demonstrate a new optical spin Hall effect manifestation and develop a magnetic field imaging system.

Main Methods:

• Fabrication of a silicon nanoparticle on a metal-dielectric waveguide.
• Excitation of waveguide modes (TE or TM) to induce magnetic resonance in the nanoparticle.
• Demonstration of optical spin Hall effect via a rotating magnetic dipole.
• Development of a scanning imaging system utilizing polarization response for magnetic field mapping.

Main Results:

• A selective magnetic coupling system with significant polarization dependence was achieved.
• A novel optical spin Hall effect was observed, leading to unidirectional emission of TE-type waveguide modes.
• The system successfully mapped transverse or longitudinal magnetic field components based on MDW type.

Conclusions:

• The proposed system offers selective magnetic resonance coupling for silicon nanoparticles on MDWs.
• This technology enables polarization-sensitive manipulation of light-matter interactions.
• The developed imaging system is valuable for fundamental magnetic field studies and nano-applications.