Fabrication of embedded plasmonic micropillars for nano-optomechanics and quantum light emission with 2D materials

The intense light-matter interactions in 2D materials can be deterministically tuned with external stimuli such as localized strain. Further, the atomically thin structure of 2D materials allows them to be precisely positioned to nanophotonic antennas that are designed to manipulate and further enhance their light-matter interactions. Nano-optical antennas embedded in dielectric cavities present new opportunities for nanophotonic engineering and nano-optomechanics in 2D materials, with applications spanning from on-demand single-photon emitters to low-temperature, high Q-factor optomechanical resonators. Here, the fabrication of metallic micropillars embedded in an SiO2 dielectric cavity is described alongside photoluminescence and atomic force microscopy characterization of single- and few-layer WSe2 crystallites that have been transferred onto the micropillar. The proof-of-concept fabrication process demonstrates that the height of the embedded pillars can be tuned to either rise above or below the cavity with nanoscale precision and sets the stage for deeper miniaturization of the micropillar and the cavity using nanofabrication techniques. This precision will prove crucial for future investigations of optomechanical interactions between a plasmonic dipole tip and a 2D heterostructure with a graphene layer and the ability for such a system to modulate 2D semiconductor phenomena such as exciton funneling and quantum light emission.