Van der Waals Materials for Applications in Nanophotonics

Abstract

Numerous optical phenomena and applications have been enabled by nanophotonic structures. Their current fabrication from high refractive index dielectrics, such as silicon or gallium phosphide, pose restricting fabrication challenges, while metals, relying on plasmons and thus exhibiting high ohmic losses, limit the achievable applications. Here, we present an emerging class of layered so-called van der Waals (vdW) crystals as a viable nanophotonics platform. We extract the dielectric response of 11 mechanically exfoliated thin-film (20-200 nm) van der Waals crystals, revealing high refractive indices up to n = 5, pronounced birefringence up to $\Delta$n = 3, sharp absorption resonances, and a range of transparency windows from ultraviolet to near-infrared. We then fabricate nanoantennas on SiO${}_2$ and gold utilizing the compatibility of vdW thin films with a variety of substrates. We observe pronounced Mie resonances due to the high refractive index contrast on SiO${}_2$ leading to a strong exciton-photon coupling regime as well as largely unexplored high-quality-factor, hybrid Mie-plasmon modes on gold. We demonstrate further vdW-material-specific degrees of freedom in fabrication by realizing nanoantennas from stacked twisted crystalline thin-films, enabling control of nonlinear optical properties, and post-fabrication nanostructure transfer, important for nano-optics with sensitive materials.

References in corpus (7)

• Measurement of the optical dielectric function of transition metal dichalcogenide monolayers: MoS2, MoSe2, WS2 and WSe2
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Cited by in corpus (9)

• Van der Waals Nanoantennas on Gold as Hosts for Hybrid Mie-Plasmonic Resonances
• Tunable Nanostructuring for van der Waals Materials
• Interface second harmonic generation enhancement in hetero-bilayer van der Waals nanoantennas
• Ultrafast all-optical switching in nonlinear 3R-MoS${}_2$ van der Waals metasurfaces
• Realization of Z${}_2$ topological photonic insulators made from multilayer transition metal dichalcogenides
• Computational discovery of high-refractive-index van der Waals materials: The case of HfS${}_2$
• Record Index-Bandgap Trade-off: CdPS3 as a High-Index van der Waals Platform for Ultraviolet-Visible Nanophotonics
• Near-field refractometry of van der Waals crystals
• Dual-Polarization SHG Interferometry for Imaging Antiparallel Domains and Stacking Angles of 2D Heterocrystals