| 摘要 |
PURPOSE:To shift the operation wavelength of a functional optical fiber by providing a core to which an active material such as a rare earth element is added and a clad which surrounds the core and has a lower refractive index than the core and further providing a stress inducing structure. CONSTITUTION:The functional optical fiber is composed of the core 12 made of phosphate glass to which Nd<3+> is added as the active material, the clad 13 made of phosphate glass to which Nd<3+> is not added, and a stress inducing jacket 11. Glass which has a larger coefficient of linear expansion than the clad 13 is used for the jacket 11. A rod for the core and pipes for the clad and jacket are formed of respective materials and the optical fiber is formed by a rod-in-tube method. The jacket 11 has the larger coefficient of linear expansion than other glass materials, so compressive stress is applied to the core 12 and jacket 13. |
