| 摘要 |
PURPOSE:To improve measurement accuracy by adding an aligning mechanism to a connection terminal of an optical fiber to be measured and aligning the optical fiber to be measured and a fiber core on a measuring instrument side with each other before the start of measurement. CONSTITUTION:The optical fiber 25 to be measured is connected to the connection connector 24 of the measuring instrument. A switch 30 is switched to a side (b) prior to the level measurement of reflected light. Laser beam from a laser beam source 21 is guided to the optical fiber 25 to be measured through the connection connector 24 and backward scattered light from this optical fiber is light-received by a light receiving device 26 through a directional coupler 23. Then aligning mechanisms 31-33 are so driven that the level of the backward scattered light detected by the light receiving device 26 is maximum, thereby aligning the connection terminal of the optical fiber 25 to be measured. In this state, the switch 30 is switched to a side (a) and the measurement is started. Consequently, the maximum incident light is guided to the optical fiber 25 to be measured at the time of the measurement and the dynamic range of the backward scattered light to be measured becomes wide, so the accuracy of the measurement is improved. |
