Year: 2025
Type: article
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-MoS2, 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-MoS2 metasurfaces supporting quasi-bound states in the continuum (qBIC), we first demonstrate SHG efficiency enhancement exceeding 102. Additionally, by using degenerate pump-probe spectroscopy, we harness the C 3v 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-MoS2 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.
Source: npj Nanophotonics
Language: English
Field: Materials Science
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $2,090
OpenAlex ID: W4413919317