E. M. Kim

Surface-Enhanced Optical Third-Harmonic Generation in Ag Island Films

Surface-enhanced optical third-harmonic generation (THG) is observed in silver island films. The THG intensity from Ag nanoparticles is enhanced by more than 2 orders of magnitude with respect to the THG intensity from a smooth and homogeneous silver surface. This enhancement is attributed to a local plasmon excitation and resonance of the local field at the third-harmonic wavelength. The diffuse and depolarized component of the enhanced THG is associated with the third-order hyper-Rayleigh scattering in a two-dimensional random array of silver nanoparticles.

Magnetophotonic crystals based on yttrium-iron-garnet infiltrated opals: Magnetization-induced second-harmonic generation

Three-dimensional magnetophotonic crystals (MPCs) based on artificial opals infiltrated by yttrium iron garnet (YIG) are fabricated and their structural, optical, and nonlinear optical properties are studied. The formation of the crystalline YIG inside the opal matrix is checked by x-ray analysis. Two templates are used for the infiltration by YIG: bare opals and those covered by a thin platinum film. Optical second-harmonic generation (SHG) technique is used to study the magnetization-induced nonlinear-optical properties of the composed MPCs. A high nonlinear magneto-optical Kerr effect in the SHG intensity is observed at the edge of the photonic band gap of the MPCs.

One-dimensional photonic crystals based on porous n-type silicon

Photonic crystals (PC) based on porous n‐Si are fabricated and their structural, optical, and nonlinear optical properties are studied. The n‐Si based PC composed of five pairs of layers with alternate porosity reveal a rather broad photonic band gap (PBG) of more than 100 nm and a reflectivity of up to 0.75. An average pore diameter of approximately 90 nm is found in n‐Si based PC in contrast to mesoporous p‐Si based PC, where pores are approximately 15 nm in diameter. Second-harmonic generation (SHG) spectroscopy reveals the enhancement of the SHG intensity by a factor of 102 at the blue edge of the PBG spectra which is attributed to the fulfillment of the phase matching conditions and the localization of the fundamental optical field in the PC.

Magnetization-induced optical third-harmonic generation in Co and Fe nanostructures

Magnetization-induced optical third-harmonic generation (MTHG) is observed in magnetic nanostructures: Co and Fe nanolayers and granular films containing Co nanoparticles. Magnetization-induced variations of the MTHG characteristics in these nanostructures exceed the typical values of linear magneto-optical Kerr effect by at least an order of magnitude: the maximum of magnetic contrast in the MTHG intensity is up to 0.2, the angle of polarization rotation for MTHG is 10ifmmode^circelsetextdegreefi{}, and the relative phase shift is up to 100ifmmode^circelsetextdegreefi{}. Correlation between the concentration dependencies of magnetic contrast in MTHG intensity and coefficient of giant magnetoresistance is observed below the percolation threshold in

Ferroelectric photonic crystals based on nanostructured lead zirconate titanate

{mathrm{Co}}_{x}{mathrm{Ag}}_{1ensuremath{-}x}

Giant third optical harmonic generation in island silver films

films. This points out the probable relations between mechanisms of these transport and nonlinear magneto-optical phenomena.

Magnetization-Induced Third Harmonic Generation in Magnetic Nanogranular Films: Correlation with Giant Magnetoresistance

The first results obtained in the synthesis of one-dimensional ferroelectric photonic crystals based on nanostructured lead zirconate titanate and porous silicon are reported. The samples synthesized are studied using linear reflection and second optical harmonic spectroscopy.

Hyper-Rayleigh light scattering in the third harmonic generation in silver island films

Giant third optical harmonic (TH) generation has been experimentally observed in island silver films. The TH intensity in the island silver films studied is more than two orders of magnitude higher than the value observed for the smooth surface of a homogeneous silver film. The mechanism of enhancement of the nonlinear cubic response is associated with the resonance enhancement of the local optical field at the TH wavelength, which is caused by the excitation of local surface plasmons in the ensemble of metal nanoparticles.

Structural studies of silver island films probed by hyper-Rayleigh scattering and atomic force microscopy

Magnetization-induced third harmonic (TH) generation was observed in magnetic nanostructures—nanogranular CoxAg1− x films—possessing giant magnetoresistance (GMR). The magnetization-induced contribution to the TH intensity was studied as a function of the concentration of a magnetic component (cobalt) in the films. Magnetic contrast of the TH intensity was found to correlate with the GMR coefficient: both parameters simultaneously reach extremum in the range of cobalt concentrations x∼0.3–0.35.

Cubic and quadratic nonlinear magneto-optical Kerr effect in magnetic nanogranular films

Hyper-Rayleigh scattering in the third harmonic generation (incoherent optical third harmonic) was experimentally observed in spatially inhomogeneous, quasi-two-dimensional structures formed by silver island films. A comprehensive analysis of the linear and nonlinear light scattering in combination with the results of atomic-force microscopy revealed the fractal nature of the island films studied in the experiment.