| 摘要 |
PURPOSE:To calculate structural parameters such as a core diameter, a clad diameter, refractive index distribution or the like by one measurement, by allowing light to transmit through an optical fiber while allowing the same to be incident to one terminal of said optical fiber and irradiating separate light from the other terminal of said optical fiber to reflect the same while simultaneously picking up the images of the transmitted light and the reflected light. CONSTITUTION:Light is allowed to be incident to one terminal A of an optical fiber 2 from a light source 12 to be transmitted through said fiber 2 while light from a light source 12 is allowed to irradiate the other terminal B of the fiber 2 and reflected. The images of the transmitted light and the reflected light are simultaneously picked up by a video camera 16 and the light intensity distribution S obtained by image picking-up is measured while moved by a minute distance along the straight line X traversing the center of the optical fiber 2 and a light intensity level I0 highest in frequency is judged as a clad level. From this result, a core diameter d1 and a clad diameter d2 are calculated. Through the comparison of the optical fiber with a known refractive index, refractive index difference is calculated. Because the images of the transmitted light and reflected light are simultaneously picked up, structural parameters can be measured by one measurement. |
