A research team from Tohoku University and Kyocera Corp. has developed a new magneto-optical material—a nanocomposite magnetic garnet film—that can be deposited directly onto silicon substrates while delivering a magneto-optical figure of merit four times higher than conventional polycrystalline films.

Using this material, the team demonstrated a monolithically integrated optical isolator on a silicon chip that matches the performance of conventional devices but with a far simpler, seed-layer-free structure. The breakthrough opens a practical path toward large-scale deployment of silicon photonics in AI-era data centers.

The work is published in the journal ACS Applied Optical Materials.