Yttrium iron garnets, which are typically used as magneto-optical isolators, are not suitable for monolithic integration with photonic circuits. We experimentally demonstrated an ultracompact microring optical isolator using an aluminum-substituted cobalt ferrite (CAFO) thin film directly deposited on silicon waveguides. The device footprint was only 43×71µm2. The isolator can operate without an external magnet owing to the strong remanent magnetization of the CAFO film and achieved a maximum isolation ratio of 24.7 dB at a wavelength of 1545.7 nm. Our study could facilitate integration of nonreciprocal photonic devices on Si platforms.

中文翻译：

---

使用铝替代钴铁氧体薄膜的超紧凑微环光隔离器


通常用作磁光隔离器的钇铁石榴石不适合与光子电路单片集成。我们通过实验演示了一种超紧凑微环光学隔离器，该隔离器使用直接沉积在硅波导上的铝取代钴铁氧体 (CAFO) 薄膜。器件占地面积仅为 43×71μm 2 。由于CAFO薄膜具有很强的剩磁，该隔离器无需外部磁体即可工作，并在1545.7 nm波长下实现了24.7 dB的最大隔离比。我们的研究可以促进不可逆光子器件在硅平台上的集成。