In this Letter, we calculate the optical and magneto-optical reflectivity in a dielectric/gap/ferromagnet excited by a -polarized monochromatic optical beam through the prism (Otto configuration) as a function of the angle of incidence and the gap thickness . Besides the well-known surface plasmon polariton (SPP resonance at ∼ ), we find a new, to the best of our knowledge, resonance with a nanometric gap ∼ 10 nm at a large ∼ 80°. Both resonances display pronounced resonant behavior in the transverse magneto-optical Kerr effect (T-MOKE).
View Article and Find Full Text PDFFemtosecond (fs) time-resolved magneto-optics is applied to investigate laser-excited ultrafast dynamics of one-dimensional nickel gratings on fused silica and silicon substrates for a wide range of periodicities Λ = 400-1500 nm. Multiple surface acoustic modes with frequencies up to a few tens of GHz are generated. Nanoscale acoustic wavelengths Λ/ have been identified as -spatial harmonics of Rayleigh surface acoustic wave (SAW) and surface skimming longitudinal wave (SSLW), with acoustic frequencies and lifetimes being in agreement with theoretical calculations.
View Article and Find Full Text PDFThe laser ultrasound (LU) technique has been used to determine dispersion curves for surface acoustic waves (SAW) propagating in AlScN/AlO systems. Polar and non-polar AlScN thin films were prepared by magnetron sputter epitaxy on AlO substrates and coated with a metal layer. SAW dispersion curves have been measured for various propagation directions on the surface.
View Article and Find Full Text PDFWe present a new approach to femtosecond direct laser writing lithography to pattern nanocavities in ferromagnetic thin films. To demonstrate the concept, we irradiated 300 nm thin nickel films by single intense femtosecond laser pulses through glass substrate. Using a fluence above the ablation threshold, the process is destructive, leading to the formation of an ablation crater.
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