F. Jonsson

Generation of Traveling Surface Plasmon Waves by Free-Electron Impact

The injection of a beam of free 50 keV electrons into an unstructured gold surface creates a highly localized source of traveling surface plasmons with spectra centered below the surface plasmon resonance frequency. The plasmons were detected by a controlled decoupling into light with a grating at a distance from the excitation point. The dominant contribution to the plasmon generation appears to come from the recombination of d-band holes created by the electron beam excitation.

Hyperspectral imaging of plasmonic nanostructures with nanoscale resolution

We report on the first realization of a hyperspectral imaging technique for surface plasmon polaritons on metallic nanostructures. The technique uses a scanning electron beam and allows for simple visualization of light emission from decoupled plasmons, providing information on decay lengths and feature sizes with nanometer resolution.

Polymorphic nanoparticles as all-optical memory elements

A nanoparticle undergoing light-induced transformations between structural phases with different optical properties is an inheritably bistable structure and this bistability can be used to create a resonator-free optical memory element, operating at very low power levels. We experimentally demonstrate this memory functionality using a film of gallium nanoparticles, and we present a method for differentially accessing the logic state of the memory using a modulated optical probe beam.

Spectral windowing with chirped magneto-optical Bragg gratings

We present a theory on a novel class of magneto-optical devices operated by means of magneto-optically induced refractive-index perturbations in chirped Bragg gratings. The predicted effect of the introduced perturbation is an opening of a narrow transmission window in the band-blocking transmission of the chirped grating. The narrow transmission window is tunable in wavelength, and relative transmission and the effects of multiple, spatially separated perturbations can also be superimposed, hence allowing for tunable, magneto-optically operated, multichannel add-drop multiplexors suitable for modularization in integrated optics.

Luminescence readout of nanoparticle phase state

We report that the phase state of bistable gallium nanoparticles, controlled by optical or electron beam excitations, can be identified via measurements of their cathodoluminescent emission, thus offering an innovative conceptual basis for the development of high density nonvolatile phase-change memories. Changes of up to 20% in visible emission intensity are observed following low-fluence optical or electron beam induced phase switching in a monolayer of 60nm particles.

OPTICAL AMPLITUDE AND PHASE EVOLUTION IN NONLINEAR MAGNETO-OPTICAL BRAGG GRATINGS

We present a theory on stratified nonlinear magneto-photonic crystals, with arbitrary spatial distribution of the refractive index and magneto-optical coefficients. The coupled mode theory is formulated for plane waves inside the crystal, and a perturbation series of integral solutions for the spectral response of the crystal is presented. Material issues and configurations are discussed, and the described theory is applied to the calculation of transmission spectra of binary magneto-photonic crystals.

Hyperspectral imaging of plasmonic excitations induced by an Electron Beam

We report on the first realization of a hyperspectral imaging technique of surface plasmon polaritons using a scanning electron beam. The technique provides for plasmon imaging and information on decay lengths with nanometer resolution.

Hyperspectral imaging of gold dimers

We report on the first realization of a hyperspectral imaging (HSI) technique of surface plasmon polaritons excited in metallic nanostructures by a scanning electron beam. The HSI image is formed by scanning a plasmonic structure with a focused electron beam, simultaneously recording the spectra of light emission from decoupled plasmons by a spectrum analyzer. By scanning the sample in this manner, one obtains a data cube consisting of the spatial coordinates of the position of the injected electron beam and the corresponding plasmon emission spectra.

Phase-change memory functionality in gallium nanoparticles

Summary form only given. We report that the structural phase of gallium nanoparticles can be switched by optical excitation and read via their cathodoluminescence (CL) when excited by a scanning electron beam. This opens a new paradigm in developing high-density phase change optical memory elements.

Nanophotonics under a scanning electron microscope: Studying resonator-less all-optical switching and memory functionality in gallium nanoparticles

Light- and electron beam-induced structural transformations in nanoparticles of polymorphic metals provide a paradigm for achieving resonator-less all-optical switching and optical memory functionality with picojoule energy requirements.