Excitonic beam steering in an active van der Waals metasurface
arXiv:2211.09297 · doi:10.1021/acs.nanolett.3c00032
Abstract
Two-dimensional transition metal dichalcogenides (2D TMDCs) are promising candidates for ultra-thin active nanophotonic elements due to the strong tunable excitonic resonances that dominate their optical response. Here we demonstrate dynamic beam steering by an active van der Waals metasurface that leverages large complex refractive index tunability near excitonic resonances in monolayer molybdenum diselenide (MoSe2). Through varying the radiative and nonradiative rates of the excitons, we can dynamically control both the reflection amplitude and phase profiles, resulting in an excitonic phased array metasurface. Our experiments show reflected light steering to angles between -30° to 30° at three different resonant wavelengths corresponding to the A exciton, B exciton, and trion. This active van der Waals metasurface relies solely on the excitonic resonances of the monolayer MoSe2 material rather than geometric resonances of patterned nanostructures, suggesting the potential to harness the tunability of excitonic resonances for wavefront shaping in emerging photonic applications.
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Cited by in corpus (5)
- Roadmap for Photonics with 2D Materials
- Temperature-dependent excitonic light manipulation with atomically-thin optical elements
- Photonics in Flatland: Challenges and Opportunities for Nanophotonics with 2D Semiconductors
- Single-gate electro-optic beam switching metasurfaces
- Silicon nanoantennas for tailoring the optical properties of MoS2 monolayers