| 摘要 |
PURPOSE: To provide a stable optical fiber measuring equipment wherein unstable measurement due to introduction of a 1/4λplate, and parasitic signals due to fiber polarized light preservation are evaded. CONSTITUTION: This optical fiber measuring equipment is an equipment wherein the change in a measured parameter generates phase difference between two waves, and provided with the following, a Sagnac ring interferometer 2 wherein two reverse propagation waves travel, and an interferometer 2 having a polarized light splitter 6 which spacially divides the two polarized lights in the Sagnac ring interferometer 2, and a polarized light preservation double refraction fiber 7 wherein two end portions have a neutral double refraction axis, and the end portion of each polarized light preservation fiber 7 is coupled to one out of gates 6b, 6c of the polarized light splitter 6. Further a double refraction element is installed which is arranged in front of the polarized light splitter 6 and introduces optical path difference greater than the coherence length of a light source 1 between the two polarized light waves.
|
