Wideband operation of Mach-Zehnder interferomertic magneto-optical isolator using phase adjustment

A wideband operation of a magneto-optical isolator is demonstrated. The isolator is based on a Mach-Zehnder interferometer employing nonreciprocal phase shift. The wideband operation is achieved by adjusting a reciprocal phase difference in the interferometer. We designed and fabricated a wideband isolator with a magneto-optic garnet waveguide. The isolation ratio of 15-25dB was obtained in a wavelength range from 1530nm to 1640nm.