REFRACTIVE INDEX PROFILE MEASUREMENT OF OPTICAL FIBER

摘要

PURPOSE:To obtain a refractive index profile of an optical fiber with a simple optical device, by directing light from a light source to a fiber yet to be covered to measure a luminous intensity distribution of a light flowing out at a terminal. CONSTITUTION:A cover 14 is removed from the end of an optical fiber 10 and after the end face thereof is prepared, the optical fiber 10 is positioned on a fiber stage 20. Reflecting material 22 is provided between the fiber 10 and the stage 20 to enhance the uniformity of a clad mode which is excited by a tungsten light 16. Light from the tungsten light 16 excites the clad mode alone within the fiber 12, propagating along the length of the naked fiber 12 and released at the end of the fiber 12 to be projected to a visicon camera 28 through a lens 24 and an aperture 26. A luminous intensity distribution released from the end face of the fiber 10 is measured with the visicon camera 28. The refractive index profile of the optical fiber 10 can be determined by analyzing the luminous intensity distribution with a computer 32.