Interferometric optical isolator with Si gudiing layer operated in unidirectional magnetic field

An interferometric optical isolator, with a Si guiding layer, employing a nonreciprocal phase shift was studied. The optical isolator was comprised of a magneto-optic waveguide with a magnetic garnet / Si / SiO₂ structure, which was fabricated by wafer bonding technique. An optical interferometer had distinct layer structures so that a unidirectional magnetic field could be applied to the optical isolator. The optical isolator employing the nonreciprocal phase shift was designed at a wavelength of 1.55 μm. The required propagation distance of the interferometer was approximately 1 mm for isolator operation.