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

Abstract

Magnetization-induced optical third-harmonic generation (MTHG) is observed in magnetic nanostructures: Co and F e nanolayers and granular films containing Co nanoparticles. Magnetizationinduced 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 10 • and the relative phase shift is up to 100 • . PACS numbers:Magneto-optics, with its more than century-long history, remains one of the most important experimental methods in studies of magnetism. Recently, significant attention has been directed towards nonlinear magnetooptics [1]: nonlinear magneto-optical Faraday and Kerr effects in second-harmonic generation (SHG) were observed experimentally in yttrium-iron-garnet films [2], then at surfaces of magnetic metals [3], in magnetic multilayers [4] and nanogranules [5]. Experimental measurements [2-5] and theoretical estimates [6] reveal the typical magnitudes of the magnetization-induced effects in SHG: the magnetization-induced variations of the SHG intensity and rotation of the second-harmonic (SH) wave polarization, may exceed the linear magneto-optical Kerr effect (MOKE) by orders of magnitude. * Electronic address: aktsip@shg.ru † Electronic address: mur@shg.ru

Towards the nonlinear acousto-magneto-plasmonics

“…Beyond the SHG response, higher nonlinearities such as third-order susceptibility-driven magnetic third harmonic generation (mTHG) can be exploited to great effect. Indeed, mTHG allows to evaluate bulk (as compared to surface mSHG) nonlinearities and also draw analogies to the giant magnetoresistance properties in ferromagnetic nanostructures [110]. In our case, for the THG frequency to fall in the visible spectral range, one would need to apply pump excitation with a wavelength in the near-infrared spectral range [111,112].…”

Plasmonic enhancement of nonlinear magneto-optical response in nickel nanorod metamaterials

“…1. This phase shift can be measured directly using the SHG interferometry technique 26 , which converts the phase-shift between the SH fields generated for the opposite directions of the applied magnetic field into a spatial shift between two interferometric patterns. It was checked experimentally that α is less than 10…”

Nonlinear Magneto-Optics in Magnetophotonic Crystals

“…Later MSHG was observed in the broad variety of magnetic materials and structures: at magnetic surfaces under UHV conditions 14) , in planar layer magnetic geterostructures 15), 16) and magnetic nanogranular films 17), 18) . Recently nonlinear magneto-optics is extended from second-order to third-order nonlinear effects: magnetization-induced plasmon assisted THG (MTHG) was observed in magnetic nanogranular films 19) . Magnetic nanogranular films are the first composite materials where nonlinear magneto-optical effects are increased strongly because of optical field enhancement due to resonant excitation of local plasmons in magnetic nanoparticles.…”