Determining the complex second-order optical susceptibility in macroscale van der Waals heterobilayers

Abstract

We report on the experimental characterization of the second-order susceptibility in MoSe${}_2$/WS${}_2$ heterobilayers, including their hidden complex phases. To this end, we developed a heterodyne-detection scheme for second-harmonic generation and applied it to macroscale heterobilayer samples prepared using the gold-tape exfoliation method. The heterodyne scheme enabled us to distinguish the relative orientation of the crystal domains, and further, it allowed us to characterize the complex phases of the susceptibility relative to a reference quartz sample. By comparing the results from the monolayer regions and the heterobilayer region over several hundred microns of the sample area, we determined that the contribution of interlayer effects to second-harmonic generation is within the experimental uncertainty arising from the sample inhomogeneity. The results here provide fundamental quantitative information necessary for the precise design of nanophotonic systems based on stacking engineering.

References in corpus (6)

• 2D materials and van der Waals heterostructures
• Measurement of the optical dielectric function of transition metal dichalcogenide monolayers: MoS2, MoSe2, WS2 and WSe2
• Resonantly hybridised excitons in moiré superlattices in van der Waals heterostructures
• Observation of a ferro-rotational order coupled with second-order nonlinear optical fields
• Nonlinear Optical Properties of Transition Metal Dichalcogenide MX${}_2$ (M = Mo, W; X = S, Se) Monolayers and Trilayers from First-principles Calculations
• Intense femtosecond photoexcitation of bulk and monolayer MoS2

Cited by in corpus (1)

• Visible and Terahertz Nonlinear Responses in the Topological Noble Metal Dichalcogenide PdTe2