# Epoxy-inspired Nonlinear Interface Integrating Monolayer Transition-Metal Dichalcogenides with Linear Plasmonic Nanosieves

## TL;DR

This paper introduces a novel nonlinear interface combining TMDC monolayers with plasmonic nanosieves, enabling advanced control of nonlinear optical emissions such as SHG, with high efficiency and multifunctionality.

## Contribution

It presents a new integrated platform that synergizes TMDC monolayers and plasmonic nanosieves to achieve enhanced nonlinear optical functionalities.

## Key findings

- Demonstrated orbital angular momentum generation
- Achieved beam steering and polarization control
- Measured effective second-harmonic nonlinearity of ~25 nm/V

## Abstract

Although TMDC monolayers offer giant optical nonlinearity within few-angstrom thickness, it is still elusive to modulate and engineer the wavefront of nonlinear emissions. The grain size of high-quality monolayers also restricts possibilities of imparting inhomogeneous or gradient profiles of phases and amplitudes by classical light sources. Plasmonic nanosieves can support huge field enhancement and precise nonlinear phase control with hundred-nanometer pixel-level resolution, however they suffer from intrinsically weak nonlinear susceptibility. In nature, epoxy represents a strong glue whose magic adhesion comes from the bonding of two intrinsic loose and nonsticky resins. Inspired by the nature of epoxy, we report a multifunctional and powerful nonlinear interfaces via integrating transition-metal dichalcogenide (TMDC) monolayers with linear plasmonic nanosieves, which cannot be accessed by either constituents. We experimentally demonstrate orbital angular momentum (OAM) generation, beam steering, versatile polarization control and holograms and of SH emission, with the proposed nonlinear interfaces. In addition, an effective second-harmonic (SH) nonlinearity \c{hi}(2) of ~25 nm/V is obtained for such systems. This designer platform synergizes the complementary advantages of TMDC monolayer, plasmonic nanosieves, geometric phases, and field enhancement, paving a distinct avenue toward designer, multi-functional, and ultra-compact nonlinear optical devices.

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Source: https://tomesphere.com/paper/1905.11093