Sputter-Deposited Si layer for optical isolator with si guiding layer

An optical isolator with a Si guiding layer that makes use of a nonreciprocal phase shift is discussed. The Si guiding layer was sputterdeposited on a garnet substrate. The magnetooptic waveguide in the optical isolator had an air/Si/magnetic garnet structure. The Si layer deposited on the garnet substrate was analyzed by spectroscopic ellipsometry and X-ray diffraction. A rib waveguide was fabricated on the deposited Si layer and evaluated. The nonreciprocal phase shift in the magnetooptic waveguide was calculated at a wavelength of 1.55 mm. The required thickness of the magnetic-garnet cladding layer was obtained by calculating the nonreciprocal phase shift.