Large third-order nonlinear susceptibility from a gold metasurface far off the plasmonic resonance

• DOI: 10.1364/josab.36.001485
• Publication Date: 2019-05-13T14:11:50Z
• Authors: Leonardo de S. Me...; Lúcio H. Acioli; Melissa Maldonado; Jawad Naciri; Nicholas Charipar; Jake Fontana; Diego Rativa; Cid B. de Araújo; Anderson S. L. Gomes
• Keywords: 02 engineering and technology; 0210 nano-technology

A large third-order nonlinear susceptibility was measured at 1500 nm from a self-assembled metasurface composed of 2D superlattice ligand-capped gold nanospheres. self-defocusing refractive index (n2=−1.05×10−10 cm2 W−1) and absorption coefficient (α2=3.00×10−6 cm were determined using the Z-scan technique with 70 fs pulses 1 kHz. The nonlinearity response time to be 1.42 ps an Optical Kerr Gate configuration. n2 value is four orders magnitude larger, in modulus, than silica glass substrate nm. We show enhancement depends on morphology due collective near-neighbor coupling between physical origin short-wave infrared region discussed.