Feasibility of integrated optical isolator with semiconductor guiding layer fabricated by wafer direct bonding

An integrated optical isolator, employing a nonreciprocal phase shift, fabricated by wafer direct bonding technique is proposed. The optical isolator has an optical interferometer, which is composed of two tapered couplers, nonreciprocal phase shifters in two arms and a reciprocal phase shifter in one of the arms. The magneto-optic waveguide in the nonreciprocal phase shifter has a magnetic garnet-GaInAsP-InP structure, which is realised by the direct bonding technique. The theoretical and experimental results of the components for the isolator are demonstrated to investigate the feasibility of this device