@article{07c925abb29e4e7c868855783c066bb1,
title = "Ultrafast All-Optical Modulation in 2D Hybrid Perovskites",
abstract = "Two-dimensional (2D) hybrid organic-inorganic Ruddlesden-Popper perovskites (RPPs) have been recently shown to exhibit large nonlinear optical properties due to the strong excitonic effects present in their multiple quantum wells. In this work, we use nondegenerate pump-probe spectroscopy in the 600-1000 nm wavelength range to study the influence of nonlinear effects on the ultrafast dynamics of 2D RPP thin flakes. We find that, under sub-bandgap excitation, {\^a}100 nm thick perovskite sheets allow up to {\^a}2% reflectivity modulation within a 20 fs period, due to the nonlinear optical Kerr effect and two-photon absorption, surpassing by a factor of {\^a}5 the reported nonlinear performance of photonic metasurfaces and single nanoantennas. When the excitation is resonant with the excitonic absorption, the ultrafast nature of the nonlinear response is lost due to the presence of linear absorption creating long-lived free carriers. Our results suggest that 2D RPPs are potential nanoscale all-optical modulators in the visible/near-infrared waveband for applications such as ultrafast information processing, optical data transmission, and high-performance computing.",
keywords = "2D Ruddlesden-Popper perovskites, optical Kerr effect, optical switching, pump-probe spectroscopy, two-photon absorption",
author = "Gustavo Grinblat and Ibrahim Abdelwahab and Nielsen, {Michael P.} and Paul Dichtl and Kai Leng and Oulton, {Rupert F.} and Loh, {Kian Ping} and Maier, {Stefan A.}",
note = "Funding Information: The authors thank X. Chi from the Department of Chemistry and Singapore Synchrotron Light Source, National University of Singapore, for the spectroscopic ellipsometry measurements. The authors acknowledge funding provided by the EPSRC Reactive Plasmonics Programme (EP/M013812/1), the EPSRC Mathematical Fundamentals of Metamaterials Programme (EP/L024926/1), and the Lee–Lucas Chair in Physics. S.A.M. further acknowledges the Bavarian Solar Energies Go Hybrid (SolTech) programme and the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany{\textquoteright}s Excellence Strategy – EXC 2089/1 – 390776260. G.G. further acknowledges a Marie Sk{\l}odowska-Curie Fellowship. P.D. acknowledges Dstl for funding. K.P.L. acknowledges support from the National Research Foundation, Prime Minister{\textquoteright}s Office, Midsized Centre program (CA2DM), Singapore. Funding Information: The authors thank X. Chi from the Department of Chemistry and Singapore Synchrotron Light Source, National University of Singapore, for the spectroscopic ellipsometry measurements. The authors acknowledge funding provided by the EPSRC Reactive Plasmonics Programme (EP/M013812/1), the EPSRC Mathematical Fundamentals of Metamaterials Programme (EP/L024926/1), and the Lee-Lucas Chair in Physics. S.A.M. further acknowledges the Bavarian Solar Energies Go Hybrid (SolTech) programme and the Deutsche Forschungsgemeinschaft (DFG German Research Foundation) under Germany's Excellence Strategy-EXC 2089/1-390776260. G.G. further acknowledges a Marie Sk?,odowska-Curie Fellowship. P.D. acknowledges Dstl for funding. K.P.L. acknowledges support from the National Research Foundation, Prime Minister's Office, Midsized Centre program (CA2DM), Singapore. Publisher Copyright: Copyright {\textcopyright} 2019 American Chemical Society.",
year = "2019",
month = aug,
day = "27",
doi = "10.1021/acsnano.9b04483",
language = "English",
volume = "13",
pages = "9504--9510",
journal = "ACS Nano",
issn = "1936-0851",
publisher = "American Chemical Society",
number = "8",
}