Revealing Mie Resonances with Enhanced and Suppressed Second-Order Nonlinear Optical Responses in a Hexagonal-Prism-Like MoS2 Nanoparticle

Transition metal dichalcogenides (TMDC), such as molybdenum disulfide (MoS2), have attracted great interest owing to their excellent electronic and optical properties. Efficient second harmonic generation (SHG) has been successfully demonstrated in the MoS2 monolayer, in sharp contrast to the negligible SHG from the bulk material. Here, the nonlinear optical responses of hexagonal-prism-like MoS2 nanoparticles are investigated, which support Mie resonances in the near infrared spectral range. It is revealed that the Mie resonances of such a MoS2 nanoparticle can be clarified into two types, which exhibit enhanced and suppressed SHG. It is verified that the SHG from the MoS2 nanoparticle is strongly correlated with the electric field distribution at the optical resonance. For the electric quadrupole mode with an anti-symmetric electric field distribution, the SHG is greatly suppressed. As a result, a nanohole appears in the emission pattern of the SHG from the MoS2 nanoparticle. In sharp contrast, the SHG from the electric dipole mode with a symmetric electric field distribution can be one order of magnitude stronger than that from a MoS2 monolayer. The findings open new horizons for manipulating the nonlinear optical responses of TMDC nanoparticles and pave the way for realizing photonic devices.

Automated summary

In this study, the nonlinear optical responses of hexagonal-prism-like MoS2 nanoparticles were investigated, revealing their Mie resonances in the near infrared spectral range. Two types of Mie resonances were identified, showing enhanced and suppressed second harmonic generation (SHG). It was found that the SHG from the MoS2 nanoparticle is strongly influenced by the electric field distribution at the optical resonance. The findings provide new insights into manipulating the nonlinear optical responses of TMDC nanoparticles and have potential applications in photonic devices.