Wavelength and Polarization Dependence of Second-Harmonic Responses from Gold Nanocrescent Arrays
Year: 2020
Type: article
Abstract: In the developing field of nonlinear plasmonics, it is important to understand the fundamental relationship between properties of the localized surface plasmon resonance (LSPR) of metallic nanostructures and their nonlinear optical responses. A detailed understanding of nonlinear responses from nanostructures with well-characterized LSPRs is an essential prerequisite for the future design of sophisticated plasmonic systems with advanced functions to control light. In this article, we investigate the second-order harmonic (SH) responses from gold nanocrescent (Au NC) antennas which have wavelength and polarization sensitive LSPRs in the visible and near-infrared wavelength ranges. The wavelength dependence of the SH intensity exhibits spectral profiles different from dipole LSPR bands in absorbance spectra. The incident polarization angle dependence was found to vary significantly when the excitation wavelength was tuned over the dipole band. Finite-difference time-domain calculations coupled with a nonlinear hydrodynamic model were carried out for Au NC arrays to investigate the local field enhancement of the incoming fundamental and emitting SH light. The experimental and theoretical results indicate that the effects of higher-order LSPRs, such as quadrupole and multipole resonances, occurring at SH wavelengths are important in governing the SH generation process. Also, it is shown that the incident polarization angle dependence of SH signals is very strongly sensitive to nanoscale variations in the NC’s shape.
Language: English
Subfield: Biomedical Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: green
Funders: National Science Foundation, U.S. Department of Defense, Utah Science Technology and Research, University of California, Irvine, Materials Research Science and Engineering Center, Harvard University, Division of Materials Research, Division of Graduate Education, Division of Chemistry, Air Force Office of Scientific Research
Awards: Protein Structure, Dynamics, and Folding via Ultrafast Multidimensional Infrared Spectroscopy, IGERT: Nanobiosensors, Nanomaterials, and Microfluidics, G185394720, G1957824854, G2737738295, G2749893320, G2906158692, G3615803236, G4085908317, Structure and Dynamics of CO Binding to Nitrogenase via Ultrafast Vibrational Spectroscopy, G4805816520, G5366996333, The Center for Chemistry at the Space-Time Limit (CaSTL), G5600345277, G783331229, G7989153129, Next-Generation Materials for Plasmonics and Spintronics, The Center for Chemistry at the Space-Time Limit (CaSTL), G886751349
OpenAlex ID: W3081057784