Abstract: A novel technique is provided, which can secure sufficient adhesion of an Si layer and a magneto-optical material layer while avoiding occurrence of cracks when fabricating an optical nonreciprocal element by bonding the Si layer on which a rib waveguide is formed, and the magneto-optical material layer. The method includes forming a waveguide on the Si layer of an SOI substrate which is a first substrate, forming a first thin-film buffer layer on the aforesaid waveguide, forming a second thin-film buffer layer on an magneto-optical material layer deposited on a second substrate by using a same material as that of the aforesaid first thin-film buffer layer, and bonding the aforesaid first thin-film buffer layer and the aforesaid second thin-film buffer layer in placement where a light propagating in the aforesaid waveguide can be caused to generate nonreciprocal phase change by the aforesaid magneto-optical material layer.

Abstract: A novel technique is provided, which can manufacture an optical nonreciprocal element constituted of an Si waveguide layer and a magneto-optical material layer without using wafer bonding. A magneto-optical material layer is deposited on a substrate, an Si layer is deposited on the aforesaid magneto-optical material layer, a waveguide is formed on the aforesaid Si layer, and the aforesaid magneto-optical material layer is magnetized so as to be able to cause a light propagating in the aforesaid waveguide to generate a nonreciprocal phase change.

Abstract: A novel technique is provided, which can manufacture an optical nonreciprocal element constituted of an Si waveguide layer and a magneto-optical material layer without using wafer bonding. A magneto-optical material layer is deposited on a substrate, an Si layer is deposited on the aforesaid magneto-optical material layer, a waveguide is formed on the aforesaid Si layer, and the aforesaid magneto-optical material layer is magnetized so as to be able to cause a light propagating in the aforesaid waveguide to generate a nonreciprocal phase change.

Abstract: A novel technique is provided, which can secure sufficient adhesion of an Si layer and a magneto-optical material layer while avoiding occurrence of cracks when fabricating an optical nonreciprocal element by bonding the Si layer on which a rib waveguide is formed, and the magneto-optical material layer. The method includes forming a waveguide on the Si layer of an SOI substrate which is a first substrate, forming a first thin-film buffer layer on the aforesaid waveguide, forming a second thin-film buffer layer on an magneto-optical material layer deposited on a second substrate by using a same material as that of the aforesaid first thin-film buffer layer, and bonding the aforesaid first thin-film buffer layer and the aforesaid second thin-film buffer layer in placement where a light propagating in the aforesaid waveguide can be caused to generate nonreciprocal phase change by the aforesaid magneto-optical material layer.