Magneto-optic nonreciprocal phase shift in (YLa)3 (FeGa)5O12 single-mode channel waveguides

We have investigated characteristics of the nonreciprocal guided-wave phase shifter, which is one of the key elements in integrated optic isolators and circulators. Based on the external magnetic field independence of the horizontally polarized mode, we measured the nonreciprocal phase shift of the vertically polarized mode using a straight waveguide instead of the complicated interferometric structures employed in previous works. It was revealed that the nonreciprocal phase shift varies remarkably with a thickness of the waveguide and there exists the optimum film thickness for the nonreciprocal phase shifter