Semiconductor waveguide optical isolator based on nonreciprocal loss induced by ferromagnetic MnAs

We fabricated TM mode InGaAlAs∕InP active waveguide optical isolators based on the magnetically induced nonreciprocal loss. We used epitaxially grown MnAs thin films as ferromagnetic electrodes of the semiconductor active waveguide optical isolators. We demonstrated TM mode nonreciprocal propagation (8.8dB∕mm) at 1540nm with an excellent ferromagnetic electrode contact, which has greater semiconductor active waveguide optical isolator performance than that of our previously reported devices with Ni∕Fe polycrystalline electrodes.