Xiang, DaoGordon, Reuven2023-04-272023-04-2720162016-06-09Xiang, D., & Gordon, R. (2016). Nanoparticle acoustic resonance enhanced nearly degenerate four-wave mixing. ACS Photonics, 3(8), 1421–1425. https://doi.org/10.1021/acsphotonics.5b00757https://doi.org/10.1021/acsphotonics.5b00757http://hdl.handle.net/1828/15017Nanoparticles have acoustic resonances in the 10 GHz to THz range, which makes them interesting for resonantly enhanced four-wave mixing applications such as frequency conversion. Using a nearly degenerate four-wave mixing setup and comparing with Rayleigh–Gans–Debye scattering, we estimate a nonlinear refractive index, n2, of approximately 2 × 10–5 cm2/MW for 22 nm polystyrene nanospheres in water at a difference frequency of 43 GHz. This is nearly 3 orders of magnitude larger than the typical below-band-gap nonlinear response of semiconductors. This strong high-frequency response may be ideal for four-wave frequency conversion in all-optical information technologies, with appropriately chosen nanoparticle sizes.ennonlinear nanophotonicsnanoparticlesacoustic vibrationfour-wave mixingPostprintDepartment of Electrical and Computer Engineering