| 摘要 |
PURPOSE:To easily mass-produce a thin film waveguide type optical isolator in a single area type having structure where isolation ratio >=30dB is obtained by forming an intermediate layer on a garnet crystal substrate in a liquid phase epitaxial method, specifying the surface roughness of the intermediate layer and forming a waveguide layer on the intermediate layer in the liquid phase epitaxial method. CONSTITUTION:In the case of producing the thin film waveguide type optical isolator in which intermediate layer and the waveguide layer made of a magneto-optical material are successively formed on the garnet crystal substrate so that the refractive index of the intermediate layer is smaller than that of the waveguide layer, the intermediate layer 4 is formed on the garnet crystal substrate 1 in the liquid phase epitaxial method and the surface roughness (Rmax) of the intermediate layer 4 is set at <=200Angstrom , then the waveguide layer 2 is formed on the layer 4 in the liquid crystal epitaxial method. Thus, the thin film waveguide type optical isolator constituted of the substrate, the intermediate layer and the waveguide layer and having the isolation ratio >=30dB, which is traditionally said to be logically possible, is easily and practically produced with mass-productivity in the liquid phase epitaxial method. |
