Optical Nonreciprocal Devices with a Silicon Guiding Layer Fabricated by Wafer Bonding

Optical nonreciprocal devices with a silicon guiding layer fabricated by wafer bonding are proposed. The optical nonreciprocal devices are composed of a magnetooptic waveguide with a magnetic garnet/Si/SiO2 structure. Nonreciprocal characteristics are obtained by an evanescent field penetrating into the upper magnetic garnet cladding layer. Several kinds of the optical nonreciprocal device are investigated with the magneto-optic waveguide and designed at a wavelength of 1.55 (mu)m. As a preliminary experiment, wafer bonding between Gd3 Ga5 O12 and Si was studied. Wafer bonding was successfully achieved with heat treatment at 220 (degree)C in H2 ambient.