| 摘要 |
PURPOSE:To obtain the condition near to steady mode distribution with good reproducibility and to facilitate handling using a short optical fiber, by connecting an optical fiber having the same type as an optical fiber to be measured between step index type optical fibers having a large core diameter. CONSTITUTION:In a measuring apparatus wherein an exciting optical fiber 2 is connected between a light source 1 and an optical fiber 3 to be measured to measure the characteristics of the optical fiber 3 to be measured, the exciting optical fiber 2 is constituted by connecting an optical fiber 6 having the same type as the optical fiber 3 to be measured between step index type optical fibers 4, 5 having a core diameter 1.5 times that of the optical fiber to be measured. By this method, even when the step index type optical fiber 5 and the optical fiber 3 to be measured are slightly shifted axially, the exciting condition to the optical fiber 3 to be measured is kept almost constant. Therefore, the exciting mode distribution approximate to a steady mode is obtained with good reproducibility by the exciting optical fiber 2 having a relatively short length. |
