Ultrafast all-optical switching in nonlinear 3R-MoS2 van der Waals metasurfaces

Seidt, Levin; Weber, Thomas; Seredin, Albert A.; Possmayer, Thomas; Savelev, Roman; Petrov, Mihail I.; Maier, Stefan A.; Tittl, Andreas; Menezes, Leonardo de S.; Sortino, Luca (2025): Ultrafast all-optical switching in nonlinear 3R-MoS2 van der Waals metasurfaces. npj Nanophotonics, 2: 37. ISSN 2948-216X

Abstract

Second-order nonlinear optical processes are fundamental to photonics, spectroscopy, and information technologies, with material platforms playing a pivotal role in advancing these applications. Here, we demonstrate the exceptional nonlinear optical properties of the van der Waals crystal 3R-MoS 2 , a rhombohedral polymorph exhibiting high second-order optical susceptibility ( χ (2) ) and remarkable second-harmonic generation (SHG) capabilities. By designing high quality factor resonances in 3R-MoS 2 metasurfaces supporting quasi-bound states in the continuum (qBIC), we first demonstrate SHG efficiency enhancement exceeding 10 2 . Additionally, by using degenerate pump-probe spectroscopy, we harness the C 3 v system’s symmetry to realize ultrafast SHG polarization switching with near-unity modulation depth. The operation speeds are limited only by the excitation pulse duration, allowing its characterization via the nonlinear autocorrelation function. These findings establish 3R-MoS 2 as a transformative platform for nanoscale nonlinear optics, offering large conversion efficiencies and ultrafast response times for advanced pulse measurement devices, integrated photonics, and quantum technologies.
onlinear optical imaging of the armchair orientation in 2D transition metal dichalcogenides.

• Dokumententyp: Artikel (LMU)
• Organisationseinheit (Fakultäten): 17 Physik
• DFG-Fachsystematik der Wissenschaftsbereiche: Naturwissenschaften
• DFG: Gefördert durch die Deutsche Forschungsgemeinschaft (DFG) - 390776260
• DFG: Gefördert durch die Deutsche Forschungsgemeinschaft (DFG) - 423258739
• DFG: Gefördert durch die Deutsche Forschungsgemeinschaft (DFG) - 491502892