V. L. Krutyanskiy

Wide tunability of magnetoplasmonic crystals due to excitation of multiple waveguide and plasmon modes

Magnetoplasmonic crystals (MPC) composed of a 1D gold grating on top of a magnetic garnet layer made by a combined ion-beam etching technique are studied. We demonstrate that this method allows to make high-quality MPC. It is shown that MPC with a 30-40 nm thick perforated gold layer provides an effective excitation of two surface plasmon-polariton modes and several numbers of waveguide modes in the garnet layer. An enhancement of the transversal magneto-optical effect up to the value of 10(-2) is observed for all types of resonant modes, that propagate in the magnetic layer, due to magnetic-field control over the mode excitation which is promising for future photonic devices.

First and second order in magnetization effects in optical second-harmonic generation from a trilayer magnetic structure

Linear and nonlinear optical properties of a thin planar CoFe/Al2O3/CoFe structure for different angles of incidence of the fundamental radiation are studied by means of the magneto-optical Kerr effect and magnetization-induced second-harmonic generation (SHG). The composition of this multilayered structure supports the appearance of the antiferromagnetic state, which leads to nonreciprocal optical effects and is discussed in terms of the magnetic toroid moment. We show that in accordance with the phenomenological description, SHG magnetic hysteresis loops for a linearly polarized pump beam are determined by linear in magnetization M components of the SHG polarization, while for a circularly polarized pump such a description necessarily involves both linear and quadratic in M components of the nonlinear polarization. Symmetry analysis of the magnetization-induced SHG supports the differences between the cases of linear and circular polarization of the incident radiation observed in the experiment, as well as a partial suppression of first in magnetization SHG contributions. Relative values of the linear and quadratic in magnetization components of the SHG polarization are estimated for the trilayer structure and for a reference homogeneous ferromagnetic film.

High-quality Au/BIG/GGG magnetoplasmonic crystals fabricated by a combined ion-beam etching technique

In this paper we discuss a promising method for the fabrication of magnetoplasmonic crystals (MPC) based on the combined ion-beam etching technique. We show that this method allows producing high-quality planar 1D MPC structures consisting of a gold grating formed on top of a garnet-based magnetic dielectric layer. We demonstrate that resonant features of the MPC, which are determined by surface plasmon-polariton (SPP) and waveguide (WG) mode excitations, can be controlled by a proper choice of the MPC period and the stripe width. Transmission spectra of the MPCs were measured in a wide angular and wavelength range, revealing the excitation of SPP and WG modes of the orders up to m = ±3. The anomalous transmission is observed at normal incidence in the spectral region where Au/garnet SPPs are excited. High values of the linear magneto-optical intensity effect are observed in transmission through the MPC. The effect is odd with respect to the direction of the SPP propagation at the Au/garnet interface and vanishes at the edges of the Brillouin zones, where counter propagating plasmons degenerate into standing waves.

Second Order Nonlinear Spectroscopy of Nickel Nanorods

The results of optical second harmonic generation (SHG) spectroscopy in an ensemble of nickel nanorods are presented. Enhancement of the magnetic nonlinear optical Kerr effect at the fundamental wavelength (750–780 nm) is observed. The effect is attributed to resonance excitation of localized surface plasmons in nickel nanorods.

Optical harmonic generation from bright squeezed vacuum

Multi-photon processes are extremely important in optics. Optical harmonics generation, multi-photon absorption, ionization, polymerization or spectroscopy are widely used in practical applications. The efficiency of these processes depends on many factors, one of them being the statistics of the incident light. Indeed, the rate of an n-photon effect scales as the nth-order autocorrelation function g(n) of the incident light [1]. Therefore light sources with high correlation functions can enhance the efficiency of such effects by several orders in magnitude compared to coherent light with the same wavelength, pulse duration and energy per pulse. Here we demonstrate this enhancement in the generation of optical harmonics from bright squeezed vacuum (BSV), which can have thermal (g(n)=n!) or superbunched (g(n)=(2n-1)!!) statistics depending on the spectral filtering [2].