Fig. 2

The total transmission spectra of the optical isolator structures for different \(\varepsilon_{xy}\). The solid black line shows the transmission spectrum for \(\varepsilon_{xy} = 0\), solid red line for \(\varepsilon_{xy} = 0.3\) forward and the dotted red line for \(\varepsilon_{xy} = 0.3\) backward. The insets below the transmission spectra are the intensity distributions of the z component of the magnetic field, corresponding to the case of \(\varepsilon_{xy} = 0\)