| 摘要 |
PURPOSE:To obtain an optical waveguide device which is excellent in its coupling efficiency and is manufactured easily, by satisfying a prescribed condition for a focal distance of a lens, in the optical waveguide device for leading a light beam of a single mode fiber to a thin plate-like optical waveguide plate through 2 lenses. CONSTITUTION:A luminous flux projected from a single mode fiber 1 is made parallel rays, is condensed to a rectangular 9 luminous flux by the second lens 4 through a polarization element 8, and is made incident to an optical waveguide plate 5. As for this luminous flux, the polarization plane is converted by an electric field or a magnetic field in the optical waveguide plate 5, a projecting light beam is made parallel rays by the third lens 6, and is condensed onto a single mode fiber 1' by the fourth lens 8 through a polarization separating element 7. When focal distances f1, f2 of the first and second lenses 2, 4 satisfy f2=f1t/d (provided that (t) is thickness of the optical waveguide plate 5, and (d) is the diameter of a core of the fiber 1), an optical waveguide device which is excellent in its coupling efficiency and is manufactured easily is obtained. |
