Spin wave mode conversion in an in-plane magnetized microscale T-shaped YIG magnonic splitter

As one of the fundamental magnonic devices, a magnonic splitter device has been proposed and spin wave propagation in this device has been studied numerically and experimentally. In the present work, we fabricated a T-shaped magnonic splitter with 6 $\mu$m-wide three arms using a 100 nm-thick yttrium iron garnet film and, using time-resolved magneto-optic Kerr microscopy, observed that spin waves split into both, the vertical and the horizontal direction at the junction. Analyzing the results, we found that spin wave modes are converted into another during the splitting process and the splitting efficiency is dominantly dependent on the 1st order of incoming spin waves.