| 摘要 |
PURPOSE:To obtain a light having a wide light emitting spectrum without polarizing characteristic by shortening the cutoff wavelength of a single mode optical fiber added with rare earth element as compared with the oscillation wavelength of an exciting light, polishing its one side end face obliquely with respect to the central axis of the fiber, and using a band pass filter of a vertical incident piece to block the exciting light. CONSTITUTION:In a rare earth element-added optical fiber 3, erbium(Er) is added as a rare earth element to a single mode optical fiber to shorten its cutoff wavelength as compared with the wavelength of an exciting light, the end face of the fiber 3 at an exciting light source side is polished obliquely with respect to the central axis of the fiber and the other end face is polished vertically to block an exciting light. In order to transmit a natural radiating light emitted from the fiber 3, a band pass filter 4 is so inserted as to be perpendicular to the light emitted from the fiber 3. |
