| 摘要 |
PURPOSE:To improve the measurement accuracy, by replacing time measurement with distance measurement utilizing interference of light. CONSTITUTION:For a light radiating device 3 loaded with a optical fiber 4 being measured, a light source 1, semipermeable mirrors 2 and 7, a mirror 5, a light-passage-length-varying device 6 and a light-receiving unit 8 are arranged. Light from the light source 1 is divided into two parts, one of which is radiated onto the measurement-undergoing optical fiber 4 using the light-radiating device 3, and the radiated light is led to the light-receiving unit 8, and at the same time, the other half's light passage length is made to be equal to that of fiber-permeating light by the light-passage-length-varying device 6, and then, it is led to the light-receiving 8, both the lights are made to interfere with each other to form an interference pattern, and variable of light passage length at the time when clearness of the interference pattern is the maximum is measured. It is possible, by doing so, to measure the value of material dispersion of the measurement-undergoing optical fiber 3 with high accuracy. |
