Localized parametric generation of spin waves in a longitudinally magnetized Ni₈₁Fe₁₉ waveguide

We demonstrate that in a longitudinally magnetized Ni₈₁Fe₁₉ waveguide spin waves can be generated via parallel parametric generation by a microstrip antenna. By employing microfocus Brillouin light scattering spectroscopy, we show that this method provides an efficient excitation source for backward volume spin waves. We analyze the spatial distribution of the generated spin waves, proving that odd and even waveguide modes can be excited. Furthermore, we study the spin-wave propagation along the Ni₈₁Fe₁₉ waveguide, revealing that the generation process takes place underneath the antenna due to its threshold nature.