This is the final version. Available on open access from Nature Research via the DOI in this recordThe dataset associated with this article is available in ORE at https://doi.org/10.24378/exe.3004Nonlinear optical devices and their implementation into modern nanophotonic architectures are constrained by their usually moderate nonlinear response. Recently, epsilon-near-zero (ENZ) materials have been found to have a strong optical nonlinearity, which can be enhanced through the use of cavities or nano-structuring. Here, we study the pump dependent properties of the plasmon resonance in the ENZ region in a thin layer of indium tin oxide (ITO). Exciting this mode using the Kretschmann-Raether configuration, we study reflection switching properties of a 60 nm layer close to the resonant plasmon frequency. We demonstrate a thermal switching mechanism, which results in a shift in the plasmon resonance frequency of 20 THz for a TM pump intensity of 70 GW cm−2. For degenerate pump and probe frequencies, we highlight an additional two-beam coupling contribution, not previously isolated in ENZ nonlinear optics studies, which leads to an overall pump induced change in reflection from 1% to 45%.Engineering and Physical Sciences Research Council (EPSRC)Royal SocietyUS Department of Energy, Office of Basic Energy Sciences, Division of Materials Sciences and EngineeringThe original version of the Supplementary Information associated with this article contained an error in Supplementary Figure 5, in which panel c of Supplementary Figure 5 had an error on the vertical axis. The HTML of the online article has been updated to include a corrected version of the Supplementary Information. See the online correction at https://doi.org/10.1038/s41467-021-22020-7 for full information.
NOTE: the original Supplementary Information file in this record has been replaced with the corrected Supplementary Information file (on 2021-05-06)Note that there is an author correction to the supplementary information at https://doi.org/10.1038/s41467-021-22020-
