| 摘要 |
PURPOSE:To provide an optical isolator small in size, inexpensive, and simple constitution which has high productivity and flexibility as for an in-line type isolator which is used for an optical fiber amplifier between optional transmission lines. CONSTITUTION:Part of the clad 2 of an optional optical fiber 1 is removed and at that part, an additional waveguide layer 4 is formed of a magnetooptic material in parallel to the optical fiber core 3. This additional waveguide layer 4 is applied with a magnetic field by a permanent magnet, en electromagnet, etc., from outside in a direction Y perpendicular to the travel direction of light to cause nonreciprocal distributed coupling between the additional waveguide layer 4 and optical fiber 3, thus constituting the optical isolator. |
