Formation of waveguiding channels for spin waves in a laser-induced magnonic microwaveguide

In this study, a method of directional spin wave branching in a rectangular waveguide made of yttrium iron garnet induced by laser radiation is demonstrated using numerical studies. It is demonstrated that the central part of the waveguide is heated by the laser beam along its entire length, leading to the emergence of a saturation magnetization gradient in the affected region. The application of laser radiation effectively “divides” the waveguide into two independent narrow waveguide channels for spin waves, thereby enabling the observation of the phenomenon of spatial pumping of spin waves. This technique enables the modulation of spin wave propagation by directing them into either half of the waveguide, thereby establishing a tap of the spin-wave signal. This approach opens new possibilities for dynamically controlling magnon devices with high accuracy and speed, and enables the development of new types of logic elements and switches for magnon circuits.