Second Harmonic Generation from Plasmon-Polariton Excitation on Silver Diffraction Gratings: Comparisons of Theory and Experiment?

KEVIN O'DONNELL; CLAUDIO VALENCIA; MIRIAM GIGLI; RENATO TORRE; MARINA INCHAUSSANDAGUE; EUGENIO MÉNDEZ

JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS

OPTICAL SOC AMER

Lugar: Washington; Año: 2016 vol. 34 p. 27 - 37

0740-3224

We present a comparison between experimental and theoretical results for the diffraction efficiencies of the second harmonic light produced in the orders of silver diffraction gratings. The gratings considered are sinusoidal, havedepths of a few nanometers, and can produce significant surface plasmon polariton excitation at fundamental and second-harmonic frequencies. The calculations are based on a general expression for the nonlinear polarization ofthe surface of a homogeneous and isotropic medium, and the diffraction problems at the fundamental and harmonic frequencies are solved using a Rayleigh method. The silver gratings were fabricated using holographic lithographyand evaporative metal deposition techniques. The samples were illuminated with picosecond pulses of wavelength 1064 nm, and photon-counting techniques were used to study the diffracted orders at 532 nm, with absolutenormalization provided by a quartz reference. The diffracted orders exhibit anomalies and other features, many of which are related to plasmon polariton excitation at both fundamental and second-harmonic frequencies.Employing previously measured values for the nonlinear susceptibilities of a flat silver surface, remarkably good comparisons of theory and experiment are obtained for the second-harmonic order efficiencies.