| 摘要 |
PURPOSE:To realize the temp. characteristic close to zero temp. coefficient by using an oxide magnetic body having a specified garnet type structure to compound the Faraday rotational capacities of the constituent elements in the plus and the minus direction. CONSTITUTION:The magnetic body is expressed by the formula A3B5O12, where A is constituted of one or >=2 kinds among trivalent rare earth metals or trivalent Bi and B is constituted of one or >=2 kinds among trivalent transition metals or trivalent Al, Ga, Sc, and In metals. For example, >=2 kinds of oxide magnetic bodies having a garnet type structure are formed on the surface of a Gd2Ga5O12 substrate crystal 17. For example, the thin film of Y3(ScGa)0.7Fe4.3O12 is formed with epitaxial growth as the first layer 14, the thin film of Bi1Gd0.9 Lu1.1Fe5O12 is formed as the second layer 15, and the thin film of BiGd0.7Lu1.3 Fe5O12 is formed as the third layer 16. An optical isolator for removing reflection noises which are the problem of the optical fiber communication system using a semiconductor laser can be constituted by using the Faraday rotation element having said composition, and the element can be applied to a magnetic field sensor, waveguide type TM-TE mode transducing, and a waveguide type optical isolator. |
