We study the effective second-harmonic generation (SHG) susceptibility in graded metallic films by invoking the local field effects exactly and further numerically demonstrate that graded metallic films can serve as a novel optical material for producing a broad structure in both the linear and the SHG response and an enhancement in the SHG signal.

Fabio Antonio Bovino1, Maria Cristina Larciprete2, Concita Sibilia2 Maurizio Giardina1, G. Váró3 and C. Gergely4 1Quantum Optics Lab Selex-Sistemi Integrati, Genova, Italy 2Department of Basic and Applied Sciences in Engineering, Sapienza University, Rome, 3Institute of Biophysics, Biological Research Center, Hungarian Academy of Sciences, Szeged, 4Montpellier University, Charles Coulomb Labora...

Chiral spectroscopic study: The intensities of second harmonic generation chiral spectroscopy are obtained from the dispersion of the nonlinear optical susceptibility components, as a function of wavelength for helicenbisquinone thin films (see figure). A single formalism fits all the data simultaneously, and the findings constitute an important milestone towards the development of a new experi...

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Nonlinear microscopy has become an important tool for imaging biological samples such as neurons. In two photon fluorescence, a fluorophore absorbs two photons at a low energy state, one of its electrons briefly converts to a higher energy state, and it emits a single excited photon at an energy level higher than that of the absorbed photons. In second harmonic generation (SHG), laser light is ...