Wavelength, polarization and orbital angular momentum of light are important degrees of freedom for processing and encoding information in optical communication. Over the years, the generation and conversion of orbital angular momentum in nonlinear optical media has found many novel applications in the context of optical communication and quantum information processing. With that hindsight, here orbital angular momentum conversion of optical vortices through second-harmonic generation from only one atomically thin WS2 monolayer is demonstrated at room temperature. Moreover, it is shown that the valley-contrasting physics associated with the nonlinear optical selection rule in WS2 monolayer precisely determines the output circular polarization state of the generated second-harmonic vortex. These results pave the way for building future miniaturized valleytronic devices with atomic-scale thickness for many applications such as chiral photon emission, nonlinear beam generation, optoelectronics, and quantum computing.
A. Dasgupta et al., "Second-Harmonic Optical Vortex Conversion from WS₂ Monolayer," Scientific Reports, vol. 9, no. 1, Nature Publishing Group, Dec 2019.
The definitive version is available at https://doi.org/10.1038/s41598-019-45424-4
Mechanical and Aerospace Engineering
Intelligent Systems Center
Second Research Center/Lab
Center for Research in Energy and Environment (CREE)
Keywords and Phrases
Article; Chirality; Photon; Physics; Polarization; Room Temperature; Thickness
International Standard Serial Number (ISSN)
Article - Journal
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01 Dec 2019