Single mode operation of 1.5 μm TM-mode waveguide optical isolators based on the nonreciprocal-loss phenomenon

We developed a 1.5-mum-band, TM-mode waveguide optical isolator consisting of a semiconductor ridge waveguide combined with a ferromagnetic MnAs layer. The device shows single mode operation with an isolation ratio of 7.2 dB/mm at 1.53-1.55 mum wavelength.