Optical waveguide isolator based on nonreciprocal loss/gain of amplifier covered by ferromagnetic layer

The effect of nonreciprocal loss/gain of a waveguide optical amplifier cove red by an absorbing magnetooptic layer was studied for the: first time. It is shown that the optical loss/gain of;this amplifier differs for the forwa rd and backward propagation when the magnetization is perpendicular to the light propagation and lies in the him plane, Using this effect a new design of an optical isolator is proposed, which is beneficial for monolithic int egration of the optical isolator with a laser diode. A calculation predicts an isolation ratio as high as 180 dB/cm for GaAs1-xPx-Al1-xGaxAs optical a mplifier covered by a Co layer.