| 摘要 |
PROBLEM TO BE SOLVED: To provide a measurement method of a cutoff wavelength by a bending method for improving measurement accuracy by keeping side pressure received by an optical fiber by contact pressure with a mandrel below a certain value regardless of the level of skill of a measuring person. SOLUTION: In this measurement method of a cutoff wavelength, transmitted light power P1 when a bend of a diameter of 280 mm and a bend of a diameter of 60 mm are applied to an optical fiber 1 of a predetermined length, and transmitted light power P2 when only the bend of a diameter of 280 mm is applied to the optical fiber 1 are measured, and a cutoff wavelengthλc is measured from the ratio of the transmitted light power values. In the measurement method, at least a first mandrel 3 out of the first mandrel and a second mandrel 5 includes a side pressure reduction mechanism 21 reducing side pressure acting on the optical fiber 1 in winding it, whereby an excitation state is prevented from becoming unstable by the influence of the side pressure to degrade measurement accuracy. COPYRIGHT: (C)2009,JPO&INPIT
|
