Print Email Facebook Twitter Nonlinear Optical Response of a WS2Monolayer at Room Temperature upon Multicolor Laser Excitation Title Nonlinear Optical Response of a WS2Monolayer at Room Temperature upon Multicolor Laser Excitation Author Hernandez Rueda, F.J. (TU Delft QN/Kuipers Lab; Kavli institute of nanoscience Delft) Noordam, M.L. (TU Delft QN/Kuipers Lab; Kavli institute of nanoscience Delft) Komen, I. (TU Delft QN/Kuipers Lab; Kavli institute of nanoscience Delft) Kuipers, L. (TU Delft QN/Quantum Nanoscience; Kavli institute of nanoscience Delft) Department QN/Quantum Nanoscience Date 2021 Abstract Currently, the nonlinear optical properties of 2D materials are attracting the attention of an ever-increasing number of research groups due to their large potential for applications in a broad range of scientific disciplines. Here, we investigate the interplay between nonlinear photoluminescence (PL) and several degenerate and nondegenerate nonlinear optical processes of a WS2 monolayer at room temperature. We illuminate the sample using two femtosecond laser pulses at frequencies ω1 and ω2 with photon energies below the optical bandgap. As a result, the sample emits light that shows characteristic spectral peaks of the second-harmonic generation, sum-frequency generation, and four-wave mixing. In addition, we find that both resonant and off-resonant nonlinear excitation via frequency mixing contributes to the (nonlinear) PL emission at the A-exciton frequency. The PL exhibits a clear correlation with the observed nonlinear effects, which we attribute to the generation of excitons via degenerate and nondegenerate multiphoton absorption. Our work illustrates a further step toward understanding the fundamental relation between parametric and nonparametric nondegenerate optical mechanisms in transition-metal dichalcogenides. In turn, such understanding has great potential to expand the range of applicability of nonlinear optical processes of 2D materials in different fields of science and technology, where nonlinear mechanisms are typically limited to degenerate processes. Subject excitonfour-wave mixingnonlinear opticssecond-harmonic generationsum-frequency generationtransition-metal dichalcogenides To reference this document use: http://resolver.tudelft.nl/uuid:44ce9f16-56dd-4e7d-90c1-4f9ba9362e74 DOI https://doi.org/10.1021/acsphotonics.0c01567 ISSN 2330-4022 Source ACS Photonics, 8 (2), 550-556 Part of collection Institutional Repository Document type journal article Rights © 2021 F.J. Hernandez Rueda, M.L. Noordam, I. Komen, L. Kuipers Files PDF acsphotonics.0c01567.pdf 1.56 MB Close viewer /islandora/object/uuid:44ce9f16-56dd-4e7d-90c1-4f9ba9362e74/datastream/OBJ/view